U.S. patent application number 10/361505 was filed with the patent office on 2003-10-23 for resist composition for electron beam, euv or x-ray.
This patent application is currently assigned to FUJI PHOTO FILM CO., LTD.. Invention is credited to Mizutani, Kazuyoshi, Takahashi, Hyou.
Application Number | 20030198894 10/361505 |
Document ID | / |
Family ID | 27667525 |
Filed Date | 2003-10-23 |
United States Patent
Application |
20030198894 |
Kind Code |
A1 |
Mizutani, Kazuyoshi ; et
al. |
October 23, 2003 |
Resist composition for electron beam, EUV or X-ray
Abstract
A resist composition for an electron beam, EUV or X-ray
comprising (A1) a compound that has a reduction potential higher
than that of diphenyl iodonium salt and generates an acid upon
irradiation of an actinic ray or radiation.
Inventors: |
Mizutani, Kazuyoshi;
(Shizuoka, JP) ; Takahashi, Hyou; (Shizuoka,
JP) |
Correspondence
Address: |
SUGHRUE MION, PLLC
2100 PENNSYLVANIA AVENUE, N.W.
WASHINGTON
DC
20037
US
|
Assignee: |
FUJI PHOTO FILM CO., LTD.
|
Family ID: |
27667525 |
Appl. No.: |
10/361505 |
Filed: |
February 11, 2003 |
Current U.S.
Class: |
430/280.1 ;
430/270.1; 430/281.1; 430/283.1; 430/288.1; 430/296; 430/325;
430/326; 430/914; 430/919; 430/920; 430/921; 430/922; 430/925;
430/942; 430/966 |
Current CPC
Class: |
Y10S 430/121 20130101;
G03F 7/0392 20130101; Y10S 430/122 20130101; Y10S 430/126 20130101;
Y10S 430/12 20130101; Y10S 430/123 20130101; G03F 7/0382 20130101;
Y10S 430/106 20130101; Y10S 430/167 20130101; G03F 7/0045 20130101;
Y10S 430/143 20130101 |
Class at
Publication: |
430/280.1 ;
430/296; 430/942; 430/966; 430/914; 430/922; 430/925; 430/919;
430/921; 430/270.1; 430/288.1; 430/281.1; 430/283.1; 430/920;
430/325; 430/326 |
International
Class: |
G03F 007/025; G03F
007/029; G03F 007/039; G03F 007/028; G03F 007/031 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 13, 2002 |
JP |
P.2002-035685 |
Feb 15, 2002 |
JP |
P.2002-038494 |
Claims
What is claimed is:
1. A resist composition for an electron beam, EUV or X-ray
comprising (A1) a compound that has a reduction potential higher
than that of diphenyl iodonium salt and generates an acid upon
irradiation of an actinic ray or radiation.
2. A positive resist composition for an electron beam, EUV or X-ray
comprising (A1) a compound that has a reduction potential higher
than that of diphenyl iodonium salt and generates an acid upon
irradiation of an actinic ray or radiation and (BP) a polymer that
is insoluble or hardly soluble in an aqueous alkali solution but
becomes soluble in the aqueous alkali solution by the action of an
acid.
3. The positive resist composition for an electron beam, EUV or
X-ray as claimed in claim 2, wherein the compound of (A1) that has
a reduction potential higher than that of diphenyl iodonium salt
and generates an acid upon irradiation of an actinic ray or
radiation is a compound represented by formula (1), (2) or (3)
shown below. 118wherein Y represents an aryl group which may have a
substituent or an alkyl group which may have a substituent;
R.sub.1a to R.sub.8a each independently represent a hydrogen atom,
a halogen atom, a nitro group, a cyano group, a carboxy group, an
alkyl group which may have a substituent or a cycloalkyl group
which may have a substituent; R.sub.1 to R.sub.15 each
independently represent a hydrogen atom, a nitro group, a cyano
group or a trifluoromethyl group, provided that at least two of
R.sub.1 to R.sub.15 are groups selected from a nitro group, a cyano
group and a trifluoromethyl group; R.sub.16 to R.sub.27 each
independently represent a hydrogen atom, a nitro group, a cyano
group, a trifluoromethyl group or a halogen atom; y represents 0 or
1; and X.sup.- represents an anion of an alkylsulfonic acid, a
benzenesulfonic acid, a naphthalenesulfonic acid or an
anthracenesulfonic acid, having at least one member selected from a
fluorine atom, an alkyl group substituted with at least one
fluorine atom, an alkoxy group substituted with at least one
fluorine atom, an acyl group substituted with at least one fluorine
atom, an acyloxy group substituted with at least one fluorine atom,
a sulfonyl group substituted with at least one fluorine atom, a
sulfonyloxy group substituted with at least one fluorine atom, a
sulfonylamino group substituted with at least one fluorine atom, an
aryl group substituted with at least one fluorine atom, an aralkyl
group substituted with at least one fluorine atom and an
alkoxycarbonyl group substituted with at least one fluorine
atom.
4. The positive resist composition for an electron beam, EUV or
X-ray as claimed in claim 2, which further comprises (A2) a
compound that generates an acid upon irradiation of an actinic ray
or radiation and has a structure represented by any one of formulae
(I) to (III) shown below. 119wherein R.sub.1 to R.sub.37, which may
be the same or different, each represent a hydrogen atom, an alkyl
group, an alkoxy group, a hydroxy group, a halogen atom or a group
of --S--R.sub.38; R.sub.38 represents an alkyl group or an aryl
group; and X.sup.- represents an anion of an alkylsulfonic acid, a
benzenesulfonic acid, a naphthalenesulfonic acid or an
anthracenesulfonic acid, having at least one member selected from a
fluorine atom, an alkyl group substituted with at least one
fluorine atom, an alkoxy group substituted with at least one
fluorine atom, an acyl group substituted with at least one fluorine
atom, an acyloxy group substituted with at least one fluorine atom,
a sulfonyl group substituted with at least one fluorine atom, a
sulfonyloxy group substituted with at least one fluorine atom, a
sulfonylamino group substituted with at least one fluorine atom, an
aryl group substituted with at least one fluorine atom, an aralkyl
group substituted with at least one fluorine atom and an
alkoxycarbonyl group substituted with at least one fluorine
atom.
5. The positive resist composition for an electron beam, EUV or
X-ray as claimed in claim 2, which further comprises at least one
compound selected from (A3) a compound that generates a carboxylic
acid containing a fluorine atom upon irradiation of an actinic ray
or radiation and (A4) a compound that generates a carboxylic acid
free from a fluorine atom upon irradiation of an actinic ray or
radiation.
6. The positive resist composition for an electron beam, EUV or
X-ray as claimed in claim 2, wherein the polymer of (BP) that is
insoluble or hardly soluble in an aqueous alkali solution but
becomes soluble in the aqueous alkali solution by the action of an
acid is a polymer having a structural unit containing a group
represented by formula (X1) or (X2) shown below. 120wherein
R.sub.1b and R.sub.2b, which may be the same or different, each
represent a hydrogen atom or an alkyl group; R.sub.3b and R.sub.4b,
which may be the same or different, each represent a hydrogen atom,
an alkyl group which may have a substituent or a cycloalkyl group
which may have a substituent; R.sub.5b represents an alkyl group
which may have a substituent, a cycloalkyl group which may have a
substituent, an aryl group which may have a substituent or an
aralkyl group which may have a substituent; m represents an integer
of from 0 to 20; and n represents an integer of from 0 to 5;
121wherein R.sub.6b and R.sub.7b, which may be the same or
different, each represent a hydrogen atom or an alkyl group; W
represents a divalent organic group; and R.sub.8b represents an
alkyl group which may have a substituent, a cycloalkyl group which
may have a substituent, an aryl group which may have a substituent
or an aralkyl group which may have a substituent.
7. The positive resist composition for an electron beam, EUV or
X-ray as claimed in claim 2, wherein the polymer of (BP) that is
insoluble or hardly soluble in an aqueous alkali solution but
becomes soluble in the aqueous alkali solution by the action of an
acid is a polymer having a structural unit containing a tertiary
ester group that is decomposed by the action of an acid.
8. The positive resist composition for an electron beam, EUV or
X-ray as claimed in claim 2, wherein the polymer of (BP) that is
insoluble or hardly soluble in an aqueous alkali solution but
becomes soluble in the aqueous alkali solution by the action of an
acid is a polymer having a structural unit containing a
tert-butoxycarbonyl group that is decomposed by the action of an
acid.
9. A negative resist composition for an electron beam, EUV or X-ray
comprising (A1) a compound that has a reduction potential higher
than that of diphenyl iodonium salt and generates an acid upon
irradiation of an actinic ray or radiation, (BN) an alkali-soluble
resin and (C) a crosslinking agent crosslinking by the action of an
acid.
10. The negative resist composition for an electron beam, EUV or
X-ray as claimed in claim 9, wherein the compound of (A1) that has
a reduction potential higher than that of diphenyl iodonium salt
and generates an acid upon irradiation of an actinic ray or
radiation is a compound represented by formula (1), (2) or (3)
shown below. 122wherein Y represents an aryl group which may have a
substituent or an alkyl group which may have a substituent;
R.sub.1a to R.sub.8a each independently represent a hydrogen atom,
a halogen atom, a nitro group, a cyano group, a carboxy group, an
alkyl group which may have a substituent or a cycloalkyl group
which may have a substituent; R.sub.1 to R.sub.15 each
independently represent a hydrogen atom, a nitro group, a cyano
group or a trifluoromethyl group, provided that at least two of
R.sub.1 to R.sub.15 are groups selected from a nitro group, a cyano
group and a trifluoromethyl group; R.sub.16 to R.sub.27 each
independently represent a hydrogen atom, a nitro group, a cyano
group, a trifluoromethyl group or a halogen atom; y represents 0 or
1; and X.sup.- represents an anion of an alkylsulfonic acid, a
benzenesulfonic acid, a naphthalenesulfonic acid or an
anthracenesulfonic acid, having at least one member selected from a
fluorine atom, an alkyl group substituted with at least one
fluorine atom, an alkoxy group substituted with at least one
fluorine atom, an acyl group substituted with at least one fluorine
atom, an acyloxy group substituted with at least one fluorine atom,
a sulfonyl group substituted with at least one fluorine atom, a
sulfonyloxy group substituted with at least one fluorine atom, a
sulfonylamino group substituted with at least one fluorine atom, an
aryl group substituted with at least one fluorine atom, an aralkyl
group substituted with at least one fluorine atom and an
alkoxycarbonyl group substituted with at least one fluorine
atom.
11. The negative resist composition for an electron beam, EUV or
X-ray as claimed in claim 9, which further comprises (A2) a
compound that generates an acid upon irradiation of an actinic ray
or radiation and has a structure represented by any one of formulae
(I) to (III) shown below. 123wherein R.sub.1 to R.sub.37, which may
be the same or different, each represent a hydrogen atom, a
straight chain, branched or cyclic alkyl group, a straight chain,
branched or cyclic alkoxy group, a hydroxy group, a halogen atom or
a group of --S--R.sub.38; R.sub.38 represents a straight chain,
branched or cyclic alkyl group or an aryl group; and X.sup.-
represents an anion of a benzenesulfonic acid, a
naphthalenesulfonic acid or an anthracenesulfonic acid, having at
least one member selected from a fluorine atom, a straight chain,
branched or cyclic alkyl group substituted with at least one
fluorine atom, a straight chain, branched or -cyclic alkoxy group
substituted with at least one fluorine atom, an acyl group
substituted with at least one fluorine atom, an acyloxy group
substituted with at least one fluorine atom, a sulfonyl group
substituted with at least one fluorine atom, a sulfonyloxy group
substituted with at least one fluorine atom, a sulfonylamino group
substituted with at least one fluorine atom, an aryl group
substituted with at least one fluorine atom, an aralkyl group
substituted with at least one fluorine atom and an alkoxycarbonyl
group substituted with at least one fluorine atom.
12. The negative resist composition for an electron beam, EUV or
X-ray as claimed in claim 9, which further comprises at least one
compound selected from (A3) a compound that generates a carboxylic
acid containing a fluorine atom upon irradiation of an actinic ray
or radiation and (A4) a compound that generates a carboxylic acid
free from a fluorine atom upon irradiation of an actinic ray or
radiation.
13. The negative resist composition for an electron beam, EUV or
X-ray as claimed in claim 9, wherein the crosslinking agent of (C)
crosslinking by the action of an acid is at least one compound
selected from compounds represented by formulae (2) to (4) shown
below and alkoxymethylated melamine compounds. 124wherein,
R.sub.5b's each independently represents a hydrogen atom, an alkyl
group or an acyl group; R.sub.6b to R.sub.9b each independently
represent a hydrogen atom, a hydroxy group, an alkyl group or an
alkoxy group; and X represents a single bond, a methylene group or
an oxygen atom.
14. The negative resist composition for an electron beam, EUV or
X-ray as claimed in claim 9, wherein the crosslinking agent of (C)
crosslinking by the action of an acid is a compound selected from
phenol derivatives having from 1 to 6 benzene rings and two or more
hydroxymethyl groups and/or alkoxymethyl groups connected to any of
the benzene rings per molecule.
15. The positive resist composition for an electron beam, EUV or
X-ray as claimed in claim 5, wherein the compound of (A3) that
generates a carboxylic acid containing a fluorine atom upon
irradiation of an actinic ray or radiation is a compound
represented by any one of formulae (IF) to (IIIF) shown below.
125wherein R.sub.1 to R.sub.37 each independently represent a
hydrogen atom, a straight chain, branched or cyclic alkyl group, a
straight chain, branched or cyclic alkoxy group, a hydroxy group, a
halogen atom or a group of --S--R.sub.38; R.sub.38 represents a
straight chain, branched or cyclic alkyl group or an aryl group;
and X.sup.- represents an anion of an aliphatic or aromatic
carboxylic acid substituted with at least one fluorine atom.
16. The positive resist composition for an electron beam, EUV or
X-ray as claimed in claim 5, wherein the compound of (A4) that
generates a carboxylic acid free from a fluorine atom -upon
irradiation of an actinic ray or radiation is a compound
represented by any one of formulae (AI) to (AV) shown below.
126wherein R.sub.301 to R.sub.337 each independently represent a
hydrogen atom, a straight chain, branched or cyclic alkyl group, a
straight chain, branched or cyclic alkoxy group, a hydroxy group, a
halogen atom or a group of --S--R.sub.0; R.sub.0 represents a
straight chain, branched or cyclic alkyl group or an aryl group;
R.sub.a and R.sub.b each independently represent a hydrogen atom, a
nitro group, a halogen atom, an alkyl group which may have a
substituent or an alkoxy group which may have a substituent;
R.sub.c and R.sub.d each independently represent a halogen atom, an
alkyl group which may have a substituent or an aryl group which may
have a substituent, or R.sub.c and R.sub.d may be combined with
each other to form an aromatic ring or a monocyclic or polycyclic
hydrocarbon ring (the ring may contain an oxygen atom or a nitrogen
atom); Y.sub.1 and Y.sub.2 each represent a carbon atom, and the
Y.sub.1--Y.sub.2 bond may be a single bond or a double bond;
X.sup.- represents an anion of at least one of carboxylic acid
compounds represented by formulae shown below; and X.sub.1 and
X.sub.2 each independently represent an ester group formed at the
carboxy group of at least one of the carboxylic acid compounds
represented by formulae shown below. 127128wherein R.sub.338
represents a straight chain, branched or cyclic alkyl group having
from 1 to 30 carbon atoms (wherein the alkyl group may contain an
oxygen atom or a nitrogen atom in the chain thereof), a straight
chain, branched or cyclic alkenyl group having from 1 to 20 carbon
atoms, a straight chain, branched or cyclic alkynyl group having
from 1 to 20 carbon atoms, a straight chain, branched or cyclic
alkoxy group having from 1 to 20 carbon atoms, the above alkyl
group in which at least a part of the hydrogen atoms is substituted
with a halogen atom and/or a hydroxy group, the above alkenyl group
in which at least a part of the hydrogen atoms is substituted with
a halogen atom and/or a hydroxy group or a substituted or
unsubstituted aryl group having from 6 to 20 carbon atoms;
R.sub.339 represents a single bond, a straight chain, branched or
cyclic alkylene group having from 1 to 20 carbon atoms (wherein the
alkylene group may contain an oxygen atom or a nitrogen atom in the
chain thereof), a straight chain, branched or cyclic alkenylene
group having from 1 to 20 carbon atoms, the above alkylene group in
which at least a part of the hydrogen atoms is substituted with a
halogen atom and/or a hydroxy group, the above alkenylene group in
which at least a part of the hydrogen atoms is substituted with a
halogen atom and/or a hydroxy group or an alkoxyalkylene group
having from 2 to 20 carbon atoms; the plural R.sub.338's and
R.sub.339's may be the same or different from each other; R.sub.340
represents a hydroxy group or a halogen atom; the plural
R.sub.340's may be the same or different from each other; m, n, p
and q each independently represent an integer of from 0 to 3,
provided that m+n.ltoreq.5 and p+q .ltoreq.5; and z represents 0 or
1.
17. The negative resist composition for an electron beam, EUV or
X-ray as claimed in claim 9, wherein the alkali-soluble resin of
(BN) is a resin containing a repeating unit represented by the
following formula (a): 129wherein R.sub.1 represents a hydrogen
atom, a halogen atom, a cyano group, an alkyl group which may have
a substituent or a haloalkyl group which may have a substituent;
R.sub.2 represents a hydrogen atom, an alkyl group which may have a
substituent, a cycloalkyl group which may have a substituent, an
aryl group which may have a substituent, an aralkyl group which may
have a substituent or an acyl group which may have a substituent;
R.sub.3 and R.sub.4, which may be the same or different, each
represent a hydrogen atom, a halogen atom, a cyano group, an alkyl
group which may have a substituent, a cycloalkyl group which may
have a substituent, an alkenyl group which may have a substituent,
an aralkyl group which may have a substituent or an aryl group
which may have a substituent; A represents a single bond, an
alkylene group which may have a substituent, an alkenylene group
which may have a substituent, a cycloalkylene group which may have
a substituent, an arylene group which may have a substituent,
--O--, --SO.sub.2--, --O--CO--R.sub.5--, --CO--O--R.sub.6-- or
--CO--N(R.sub.7)--R.sub.8--; R.sub.5, R.sub.6 and R.sub.8, which
may be the same or different, each represent a single bond, an
alkylene group which may have a substituent, an alkenylene group
which may have a substituent, a cycloalkylene group which may have
a substituent, an arylene group which may have a substituent, a
divalent group formed by combining the above-described alkylene,
alkenylene, cycloalkylene or arylene group and at least one member
selected from an ether structure, an ester structure, an amido
structure, a urethane structure and a ureido structure; R.sub.7
represents a hydrogen atom, an alkyl group which may have a
substituent, a cycloalkyl group which may have a substituent, an
aralkyl group which may have a substituent or an aryl group which
may have a substituent; n represents an integer of from 1 to 3; or
plural R.sub.2's, R.sub.2 and R.sub.3 or R.sub.2 and R.sub.4 may be
combined with each other to form a ring.
18. The resist composition for an electron beam, EUV or X-ray as
claimed in claim 1, which further comprises an organic basic
compound containing a structure represented by the following
formula (A), (B), (C), (D) or (E): 130wherein R.sup.250, R.sup.251
and R.sup.252, which may be the same or different, each represent a
hydrogen atom, an alkyl group having from 1 to 6 carbon atoms, an
aminoalkyl group having from 1 to 6 carbon atoms, a hydroxyalkyl
group having from 1 to 6 carbon atoms or a substituted or
unsubstituted aryl group having from 6 to 20 carbon atoms, or
R.sup.251 and R.sup.252 may be combined with each other to form a
ring; and R.sup.253, R.sup.254, R.sup.255 and R.sup.256, which may
be the same or different, each represent an alkyl group having from
1 to 6 carbon atoms.
19. The resist composition for an electron beam, EUV or X-ray as
claimed in claim 1, which further comprises a fluorine-based and/or
silicon-based surface active agent.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a resist composition
suitable for use in an ultra-micro lithographic process, for
example, the production of VLSI and high-capacity microchips, and
other photofabrication processes. More specifically, the present
invention relates to a positive resist composition and negative
resist composition capable of forming high precision patterns using
an electron beam, EUV or an X-ray.
BACKGROUND OF THE INVENTION
[0002] In integrated circuits, the degree of integration has more
and more increased and in the production of a semiconductor
substrate such as VLSI, processing of super-fine patterns composed
of line width having a half-micron or less has been required. In
order to satisfy such a requirement, the wavelength of an exposure
apparatus used for a photolithography has more and more shortened
and at present, the use of a far ultraviolet light and an excimer
laser (e.g., XeCl, KrF or ArF) is investigated. Furthermore, the
formation of finer patterns by an electron beam or an X-ray has
been investigated.
[0003] The electron beam lithography is regarded as the next
generation pattern formation technique or the pattern formation
technique after the next generation, and the development of a
positive resist and negative resist having high sensitivity, high
resolution and a rectangular profile forming property has been
strongly desired.
[0004] According to the electron beam lithography, accelerated
electron beams collide with atoms constituting a resist material
and scatter to supply energy to compounds and as a result, the
reaction of resist material occurs, whereby an image is formed. To
use highly accelerated electron beams increases the rectilinear
propagation of electron beams and decreases the influence of
electron scattering so that it makes possible the formation of
pattern having high resolution, rectangular profile and excellent
edge roughness. On the other hand, however, the transmittance of
electron beam increases, resulting in decrease in sensitivity.
Thus, a trade off relation between the sensitivity and the
resolution, resist profile and edge roughness exists in the
electron beam lithography, and it is a problem to be solved to
fulfill requirements for both the sensitivity and the resolution,
resist profile and edge roughness. EUV lithography and X-ray
lithography also have the same problem.
[0005] With respect to the positive resist for electron beam or X
ray, resist techniques for KrF excimer laser have been mainly
diverted and investigated. For instance, the combination use of a
compound capable of generating an acid upon electron beam
irradiation and an amine compound having a boiling point of not
more than 250.degree. C. as described in JP-A-2000-181065 (the term
"JP-A" as used herein means an "unexamined published Japanese
patent application"), the combination use of a polymer having an
acid decomposable group, an acid generator and an electron beam
sensitizer as described in European Patent 919, 867, and the
combination use of a polymer having an acid decomposable group and
an amide compound as described in JP-W-7-508840 (the term "JP-W" as
used herein means an "unexamined published international patent
application") are known. Further, the use of a maleimide compound
as described in JP-A-3-200968, the use of a sulfonamide compound as
described in JP-A-7-92680, and the use of a sulfonimide compound
including a partial structure of --SO.sub.2--NH--SO.sub.2-- as
described in JP-A-11-44950 are known. However, these attempts do
not solve the problem to fulfill all requirements of high
sensitivity, high resolution, good rectangular resist profile and
excellent edge roughness.
[0006] On the other hand, with respect to chemical amplification
negative resists, various alkali-soluble resins have been proposed.
The use of polyvinyl phenol partially alkyl etherized is described
in JP-A-8-152717. The use of copolymer of vinyl phenol and styrene
is described in JP-A-6-67431 and JP-A-10-10733. The use of novolac
resin is described in Japanese Patent 2,505,033. The use of
monodispersed polyvinyl phenol is described in JP-A-7-311463 and
JP-A-8-292559. However, it could not be achieved to fulfill all
characteristics of the sensitivity, resolution, resist profile and
edge roughness upon irradiation of electron beam or X-ray by using
such alkali-soluble resins.
[0007] Also, various compounds capable of generating an acid upon
irradiation of electron beam or X-ray have been proposed with
respect to the chemical amplification negative resists. The use of
organic halogen compound is described in JP-B-8-3635 (the term
"JP-B" as used herein means an "examined Japanese patent
publication") . The use of iodonium salt or sulfonium salt is
described in JP-A-2-150848 and JP-A-6-199770. The use of acid
generator containing Cl or Br is described in JP-A-2-52348,
JP-A-4-367864 and JP-A-4-367865. The use of diazodisulfone or
diazosulfone compound is described in JP-A-4-210960 and
JP-A-4-217249. The use of triazine compound is described in
JP-A-4-226454. The use of sulfonate compound is described in
JP-A-3-87746, JP-A-4-291259, JP-A-6-236024 and U.S. Pat. No.
5,344,742. However, the trade off relation between the sensitivity
and the resolution, resist profile and edge roughness upon
irradiation of electron beam or X-ray cannot be overcome by using
such acid generators.
[0008] Further, with respect to a crosslinking agent, for example,
methylol melamine, a resole resin, an epoxylated novolac resin or a
urea resin has been used. However, these crosslinking agents are
unstable to heat and have a problem of preservation stability of a
resist solution.
[0009] The resist compositions described in Japanese Patent
3,000,740, JP-A-9-166870 and JP-A-2-15270 are also insufficient for
meeting characteristic requirements of high sensitivity, high
resolution, good rectangular resist profile and excellent edge
roughness upon irradiation of electron beam or X-ray.
[0010] Therefore, it is difficult to fulfill requirements for
sufficiently high sensitivity, sufficiently high resolution, good
rectangular resist profile and excellent edge roughness all
together in hitherto known techniques and it has been strongly
desired to solve the problem.
SUMMARY OF THE INVENTION
[0011] An object of the present invention is to provide a resist
composition which resolve problems in the techniques for improving
the performance in fine processing of semiconductor device using an
electron beam, EUV or an X-ray.
[0012] Another object of the present invention is to provide a
positive resist composition that is excellent in sensitivity and
resolution in case of using an electron beam, EUV or an X-ray.
[0013] A still another object of the present invention is to
provide a positive resist composition that fulfills characteristics
of rectangular pattern profile and edge roughness as well as
sensitivity and resolution in case of using an electron beam, EUV
or an X-ray.
[0014] A further object of the present invention is to provide a
chemical amplification negative resist composition that satisfies
characteristics of sensitivity, resolution, resist profile and edge
roughness all together in case of using an electron beam, EUV or an
X-ray.
[0015] Other objects of the present invention will become apparent
from the following description.
[0016] As the result of extensive investigations, the inventors
have found that the above objects of the present invention can be
attained by a resist composition containing a specific acid
generator, and completed the present invention.
[0017] Specifically, the present invention includes the following
resist compositions:
[0018] (1) A resist composition for an electron beam, EUV or X-ray
comprising (A1) a compound that has a reduction potential higher
than that of diphenyl iodonium salt and generates an acid upon
irradiation of an actinic ray or radiation.
[0019] (2) A positive resist composition for an electron beam, EUV
or X-ray comprising (A1) a compound that has a reduction potential
higher than that of diphenyl iodonium salt and generates an acid
upon irradiation of an actinic ray or radiation and (BP) a polymer
that is insoluble or hardly soluble in an aqueous alkali solution
but becomes soluble in the aqueous alkali solution by the action of
an acid.
[0020] (3) The positive resist composition for an electron beam,
EUV or X-ray as described in item (2) above, wherein the compound
of (A1) that has a reduction potential higher than that of diphenyl
iodonium salt and generates an acid upon irradiation of an actinic
ray or radiation is a compound represented by formula (1), (2) or
(3) shown below. 1
[0021] In formula (1), Y represents an aryl group which may have a
substituent or an alkyl group which may have a substituent.
[0022] R.sub.1a to R.sub.8a each independently represent a hydrogen
atom, a halogen atom, a nitro group, a cyano group, a carboxy
group, an alkyl group which may have a substituent or a cycloalkyl
group which may have a substituent. 2
[0023] In formula (2), R.sub.1 to R.sub.15 each independently
represent a hydrogen atom, a nitro group, a cyano group or a
trifluoromethyl group, provided that at least two of R.sub.1 to
R.sub.15 are groups selected from a nitro group, a cyano group and
a trifluoromethyl group.
[0024] In formula (3), R.sub.16 to R.sub.27 each independently
represent a hydrogen atom, a nitro group, a cyano group, a
trifluoromethyl group or a halogen atom.
[0025] y represents 0 or 1.
[0026] X.sup.- represents an anion of an alkylsulfonic acid, a
benzenesulfonic acid, a naphthalenesulfonic acid or an
anthracenesulfonic acid, having at least one member selected from a
fluorine atom, an alkyl group substituted with at least one
fluorine atom, an alkoxy group substituted with at least one
fluorine atom, an acyl group substituted with at least one fluorine
atom, an acyloxy group substituted with at least one fluorine atom,
a sulfonyl group substituted with at least one fluorine atom, a
sulfonyloxy group substituted with at least one fluorine atom, a
sulfonylamino group substituted with at least one fluorine atom, an
aryl group substituted with at least one fluorine atom, an aralkyl
group substituted with at least one fluorine atom and an
alkoxycarbonyl group substituted with at least one fluorine
atom.
[0027] (4) The positive resist composition for an electron beam,
EUV or X-ray as described in item (2) or (3) above, which further
comprises (A2) a compound that generates an acid upon irradiation
of an actinic ray or radiation and has a structure represented by
any one of formulae (I) to (III) shown below. 3
[0028] In formulae (I) to (III), R.sub.1 to R.sub.37, which may be
the same or different, each represent a hydrogen atom, an alkyl
group, an alkoxy group, a hydroxy group, a halogen atom or a group
of --S--R.sub.38. R.sub.38 represents an alkyl group or an aryl
group.
[0029] X.sup.- represents an anion of an alkylsulfonic acid, a
benzenesulfonic acid, a naphthalenesulfonic acid or an
anthracenesulfonic acid, having at least one member selected from a
fluorine atom, an alkyl group substituted with at least one
fluorine atom, an alkoxy group substituted with at least one
fluorine atom, an acyl group substituted with at least one fluorine
atom, an acyloxy group substituted with at least one fluorine atom,
a sulfonyl group substituted with at least one fluorine atom, a
sulfonyloxy group substituted with at least one fluorine atom, a
sulfonylamino group substituted with at least one fluorine atom, an
aryl group substituted with at least one fluorine atom, an aralkyl
group substituted with at least one fluorine atom and an
alkoxycarbonyl group substituted with at least one fluorine
atom.
[0030] (5) The positive resist composition for an electron beam,
EUV or X-ray as described in any one of items (2) to (4) above,
which further comprises at least one compound selected from (A3) a
compound that generates a carboxylic acid containing a fluorine
atom upon irradiation of an actinic ray or radiation and (A4) a
compound that generates a carboxylic acid free from a fluorine atom
upon irradiation of an actinic ray or radiation.
[0031] (6) The positive resist composition for an electron beam,
EUV or X-ray as described in any one of items (2) to (5) above,
wherein the polymer of (BP) that is insoluble or hardly soluble in
an aqueous alkali solution but becomes soluble in the aqueous
alkali solution by the action of an acid is a polymer having a
structural unit containing a group represented by formula (X1) or
(X2) shown below. 4
[0032] In formula (X1) , R.sub.1b and R.sub.2b, which may be the
same or different, each represent a hydrogen atom or an alkyl
group.
[0033] R.sub.3b and R.sub.4b, which may be the same or different,
each represent a hydrogen atom, an alkyl group which may have a
substituent or a cycloalkyl group which may have a substituent.
[0034] R.sub.5b represents an alkyl group which may have a
substituent, a cycloalkyl group which may have a substituent, an
aryl group which may have a substituent or an aralkyl group which
may have a substituent.
[0035] m represents an integer of from 0 to 20, and n represents an
integer of from 0 to 5. 5
[0036] In formula (X2), R.sub.6b and R.sub.7b, which may be the
same or different, each represent a hydrogen atom or an alkyl
group.
[0037] W represents a divalent organic group.
[0038] R.sub.8b represents an alkyl group which may have a
substituent, a cycloalkyl group which may have a substituent, an
aryl group which may have a substituent or an aralkyl group which
may have a substituent.
[0039] (7) The positive resist composition for an electron beam,
EUV or X-ray as described in any one of items (2) to (6) above,
wherein the polymer of (BP) that is insoluble or hardly soluble in
an aqueous alkali solution but becomes soluble in the aqueous
alkali solution by the action of an acid is a polymer having a
structural unit containing a tertiary ester group that is
decomposed by the action of an acid.
[0040] (8) The positive resist composition for an electron beam,
EUV or X-ray as described in any one of items (2) to (6) above,
wherein the polymer of (BP) that is insoluble or hardly soluble in
an aqueous alkali solution but becomes soluble in the aqueous
alkali solution by the action of an acid is a polymer having a
structural unit containing a tert-butoxycarbonyl group that is
decomposed by the action of an acid.
[0041] (9) A negative resist composition for an electron beam, EUV
or X-ray comprising (A1) a compound that has a reduction potential
higher than that of diphenyl iodonium salt and generates an acid
upon irradiation of an actinic ray or radiation, (BN) an
alkali-soluble resin and (C) a crosslinking agent crosslinking by
the action of an acid.
[0042] (10) The negative resist composition for an electron beam,
EUV or X-ray as described in item (9) above, wherein the compound
of (A1) that has a reduction potential higher than that of diphenyl
iodonium salt and generates an acid upon irradiation of an actinic
ray or radiation is a compound represented by formula (1), (2) or
(3) shown below. 6
[0043] In formula (1), Y represents an aryl group which may have a
substituent or an alkyl group which may have a substituent.
[0044] R.sub.1a to R.sub.8a each independently represent a hydrogen
atom, a halogen atom, a nitro group, a cyano group, a carboxy
group, an alkyl group which may have a substituent or a cycloalkyl
group which may have a substituent. 7
[0045] In formula (2), R.sub.1 to R.sub.15 each independently
represent a hydrogen atom, a nitro group, a cyano group or a
trifluoromethyl group, provided that at least two of R.sub.1 to
R.sub.15 are groups selected from a nitro group, a cyano group and
a trifluoromethyl group.
[0046] In formula (3), R.sub.16 to R.sub.27 each independently
represent a hydrogen atom, a nitro group, a cyano group, a
trifluoromethyl group or a halogen atom.
[0047] y represents 0 or 1.
[0048] X.sup.- represents an anion of an alkylsulfonic acid, a
benzenesulfonic acid, a naphthalenesulfonic acid or an
anthracenesulfonic acid, having at least one member selected from a
fluorine atom, an alkyl group substituted with at least one
fluorine atom, an alkoxy group substituted with at least one
fluorine atom, an acyl group substituted with at least one fluorine
atom, an acyloxy group substituted with at least one fluorine atom,
a sulfonyl group substituted with at least one fluorine atom, a
sulfonyloxy group substituted with at least one fluorine atom, a
sulfonylamino group substituted with at least one fluorine atom, an
aryl group substituted with at least one fluorine atom, an aralkyl
group substituted with at least one fluorine atom and an
alkoxycarbonyl group substituted with at least one fluorine
atom.
[0049] (11) The negative resist composition for an electron beam,
EUV or X-ray as described in item (9) or (10) above, which further
comprises (A2) a compound that generates an acid upon irradiation
of an actinic ray or radiation and has a structure represented by
any one of formulae (I) to (III) shown below. 8 9
[0050] In formulae (I) to (III), R.sub.1 to R.sub.37, which may be
the same or different, each represent a hydrogen atom, a straight
chain, branched or cyclic alkyl group, a straight chain, branched
or cyclic alkoxy group, a hydroxy group, a halogen atom or a group
of --S--R.sub.38. R.sub.38 represents a straight chain, branched or
cyclic alkyl group or an aryl group.
[0051] X.sup.- represents an anion of an alkylsulfonic acid, a
benzenesulfonic acid, a naphthalenesulfonic acid or an
anthracenesulfonic acid, having at least one member selected from a
fluorine atom, a straight chain, branched or cyclic alkyl group
substituted with at least one fluorine atom, a straight chain,
branched or cyclic alkoxy group substituted with at least one
fluorine atom, an acyl group substituted with at least one fluorine
atom, an acyloxy group substituted with at least one fluorine atom,
a sulfonyl group substituted with at least one fluorine atom, a
sulfonyloxy group substituted with at least one fluorine atom, a
sulfonylamino group substituted with at least one fluorine atom, an
aryl group substituted with at least one fluorine atom, an aralkyl
group substituted with at least one fluorine atom and an
alkoxycarbonyl group substituted with at least one fluorine
atom.
[0052] (12) The negative resist composition for an electron beam,
EUV or X-ray as described in any one of items (9) to (11) above,
which further comprises at least one compound selected from (A3) a
compound that generates a carboxylic acid containing a fluorine
atom upon irradiation of an actinic ray or radiation and (A4) a
compound that generates a carboxylic acid free from a fluorine atom
upon irradiation of an actinic ray or radiation.
[0053] (13) The negative resist composition for an electron beam,
EUV or X-ray as described in any one of items (9) to (12) above,
wherein the crosslinking agent of (C) crosslinking by the action of
an acid is at least one compound selected from compounds
represented by formulae (2) to (4) shown below and alkoxymethylated
melamine compounds. 10
[0054] In formulae (2) to (4), R.sub.5b's each independently
represent a hydrogen atom, an alkyl group or an acyl group.
[0055] In formula (2), R.sub.6b to R.sub.9b each independently
represent a hydrogen atom, a hydroxy group, an alkyl group or an
alkoxy group.
[0056] X represents a single bond, a methylene group or an oxygen
atom.
[0057] (14) The negative resist composition for an electron beam,
EUV or X-ray as described in any one of items (9) to (12) above,
wherein the crosslinking agent of (C) crosslinking by the action of
an acid is a compound selected from phenol derivatives having from
1 to 6 benzene rings and two or more hydroxymethyl groups and/or
alkoxymethyl groups connected to any of the benzene rings per
molecule.
DETAILED DESCRIPTION OF THE INVENTION
[0058] The compounds constituting the resist composition according
to the present invention will be described in more detail
below.
[0059] <<(A1) Compound That has a Reduction Potential Higher
than that of Diphenyliodonium Salt and Generates an Acid Upon
Irradiation of an Actinic Ray or Radiation (Hereinafter, also
Referred to as "Component (A1)" or "Compound of (A1)">>
[0060] The compound of (A1) is used as an acid generator in the
present invention. Measurement of reduction potential of the
compound of (A1) can be carried out by cyclic voltammetry. The
compound of (A1) includes, for example, a diphenyliodonium salt
having an electron attracting group on the phenyl group, e.g.,
bis(chlorophenyl)iodonium salt and the compounds represented by
formulae (1) to (3) described above. The compounds represented by
formulae (1) to (3) are preferably used.
[0061] In formula (1), Y represents an aryl group which may have a
substituent or an alkyl group which may have a substituent.
R.sub.1a to R.sub.8a each independently represent a hydrogen atom,
a halogen atom, a nitro group, a cyano group, a carboxy group, an
alkyl group which may have a substituent or a cycloalkyl group
which may have a substituent.
[0062] The alkyl group represented by Y may be any of straight
chain and branched alkyl groups, and preferably has from 1 to 8
carbon atoms. Specific examples of the alkyl group include methyl,
ethyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, neopentyl,
hexyl, heptyl and octyl groups. The alkyl group may further have a
substituent.
[0063] The aryl group represented by Y preferably has from 6 to 16
carbon atoms. Specific examples of the aryl group include phenyl,
naphthyl, anthryl, phenanthryl and pyrenyl groups.
[0064] The substituent for the alkyl group or aryl group
represented by Y includes, for example, an aryl group, an alkyl
group, a cycloalkyl group, an alkoxy group, a carboxy group, a
hydroxy group, a halogen atom (e.g., fluorine, chlorine, bromine or
iodine atom), a cyano group, a nitro group, an arylcarbonyl group
and an alkylcarbonyl group. Of the substituents for the alkyl group
or aryl group represented by Y, an electron attracting substituent,
for example, a halogen atom (e.g., fluorine, chlorine, bromine or
iodine atom), a cyano group, a nitro group, an arylcarbonyl group
or an alkylcarbonyl group is preferred in view of the reduction
potential.
[0065] The alkyl group represented by any one of R.sub.1a to
R.sub.8a may be any of straight chain and branched alkyl groups,
and preferably has from 1 to 8 carbon atoms. Specific examples of
the alkyl group include methyl, ethyl, isopropyl, n-butyl,
isobutyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl and octyl
groups. The alkyl group may further have a substituent.
[0066] The cycloalkyl group represented by any one of R.sub.1a to
R.sub.8a preferably has from 3 to 8 carbon atoms. Specific examples
of the cycloalkyl group include cyclopropyl, cyclopentyl and
cyclohexyl groups. The cycloalkyl group may further have a
substituent.
[0067] The halogen atom represented by any one of R.sub.1a to
R.sub.8a includes, for example, fluorine, chlorine, bromine and
iodine atoms.
[0068] The substituent for the alkyl group or cycloalkyl group
represented by any one of R.sub.1a to R.sub.8a includes, for
example, an alkyl group (e.g., methyl, ethyl, n-propyl, isopropyl,
n-butyl, tert-butyl, n-amyl or tert-amyl group), a cycloalkyl
group, a phenyl group, a halogen atom (e.g., fluorine, chlorine,
bromine or iodine atom), a cyano group and a nitro group. Of the
substituents for the alkyl group or cycloalkyl group represented by
any one of R.sub.1a to R.sub.8a, an alkyl group (e.g., methyl,
ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, n-amyl or
tert-amyl group) is preferred in view of increasing the solubility
in a solvent, and an electron attracting substituent, for example,
a halogen atom (e.g., fluorine, chlorine, bromine or iodine atom),
a cyano group or a nitro group is preferred in view of the
reduction potential.
[0069] When the compound of formula (1) has a counter anion, as the
counter anion, that generates an organic sulfonic acid is
preferable and that generates an alkylsulfonic acid, an aromatic
sulfonic acid, a fluorinated alkylsulfonic acid or a fluorinated
aromatic sulfonic acid is more preferable. Of the organic sulfonic
acids, those having a large number of carbon atoms are preferred,
since diffusion of the acid generated is appropriately restrained
to improve resolution. Specifically, an alkylsulfonic acid having
from 4 to 20 carbon atoms in the alkyl group, an aromatic sulfonic
acid containing a benzene ring or naphthalene ring, a fluorinated
alkylsulfonic acid having from 4 to 12 carbon atoms in the alkyl
group and a fluorinated aromatic sulfonic acid containing a benzene
ring or naphthalene ring are preferably used.
[0070] In formula (2), R.sub.1 to R.sub.15 each independently
represent a hydrogen atom, a nitro group, a cyano group or a
trifluoromethyl group, provided that at least two of R.sub.1 to
R.sub.15 are groups selected from a nitro group, a cyano group and
a trifluoromethyl group.
[0071] In formula (3), R.sub.16 to R.sub.27 each independently
represent a hydrogen atom, a nitro group, a cyano group, a
trifluoromethyl group or a halogen atom.
[0072] y represents 0 or 1.
[0073] X.sup.- represents an anion of an alkylsulfonic acid, a
benzenesulfonic acid, a naphthalenesulfonic acid or an
anthracenesulfonic acid, having at least one member selected from a
fluorine atom, an alkyl group substituted with at least one
fluorine atom, an alkoxy group substituted with at least one
fluorine atom, an acyl group substituted with at least one fluorine
atom, an acyloxy group substituted with at least one fluorine atom,
a sulfonyl group substituted with at least one fluorine atom, a
sulfonyloxy group substituted with at least one fluorine atom, a
sulfonylamino group substituted with at least one fluorine atom, an
aryl group substituted with at least one fluorine atom, an aralkyl
group substituted with at least one fluorine atom and an
alkoxycarbonyl group substituted with at least one fluorine
atom.
[0074] The halogen atom represented by any one of R.sub.16 to
R.sub.27 includes, for example, fluorine, chlorine, bromine and
iodine atoms.
[0075] The alkyl group substituted with at least one fluorine atom
described above may be any of straight chain, branched and cyclic
alkyl groups and is preferably that having from 1 to 12 carbon
atoms and substituted with 1 to 25 fluorine atoms.
[0076] Specific examples thereof include trifluoromethyl,
pentafluoroethyl, 2,2,2-trifluoroethyl, heptafluoropropyl,
heptafluoroisopropyl, perfluorobutyl, perfluorooctyl,
perfluorododecyl and perfluorocyclohexyl groups. Among them, a
perfluoroalkyl group having from 1 to 4 carbon atoms fully
substituted with fluorine atoms is preferred. A perfluorobutyl
group is particularly preferred.
[0077] The alkoxy group substituted with at least one fluorine atom
described above may be any of straight chain, branched and cyclic
alkoxy groups and is preferably that having from 1 to 12 carbon
atoms and substituted with 1 to 25 fluorine atoms.
[0078] Specific examples thereof include trifluoromethoxy,
pentafluoroethoxy, heptafluoroisopropyloxy, perfluorobutoxy,
perfluorooctyloxy, perfluorododecyloxy and perfluorocyclohexyloxy
groups. Among them, a perfluoroalkoxy group having from 1 to 4
carbon atoms fully substituted with fluorine atoms is
preferred.
[0079] The acyl group substituted with at least one fluorine atom
described above is preferably that having from 2 to 12 carbon atoms
and substituted with 1 to 23 fluorine atoms. Specific examples
thereof include trifluoroacetyl, fluoroacetyl, pentafluoropropionyl
and pentafluorobenzoyl groups.
[0080] The acyloxy group substituted with at least one fluorine
atom described above is preferably that having from 2 to 12 carbon
atoms and substituted with 1 to 23 fluorine atoms. Specific
examples thereof include trifluoroacetoxy, fluoroacetoxy,
pentafluoropropionyloxy and pentafluorobenzoyloxy groups.
[0081] The sulfonyl group substituted with at least one fluorine
atom described above is preferably that having from 1 to 12 carbon
atoms and substituted with 1 to 25 fluorine atoms. Specific
examples thereof include trifluoromethanesulfonyl,
pentafluoroethanesulfonyl, perfluorobutanesulfonyl,
perfluorooctanesulfonyl, pentafluorobenzenesulfo- nyl and
4-trifluoromethylbenzenesulfonyl groups.
[0082] The sulfonyloxy group substituted with at least one fluorine
atom described above is preferably that having from 1 to 12 carbon
atoms and substituted with 1 to 25 fluorine atoms. Specific
examples thereof include trifluoromethanesulfonyloxy,
perfluorobutanesulfonyloxy and 4-trifluoromethylbenzenesulfonyloxy
groups.
[0083] The sulfonylamino group substituted with at least one
fluorine atom described above is preferably that having from 1 to
12 carbon atoms and substituted with 1 to 25 fluorine atoms.
Specific examples thereof include trifluoromethanesulfonylamino,
perfluorobutanesulfonylamino, perfluorooctanesulfonylamino and
pentafluorobenzenesulfonylamino groups.
[0084] The aryl group substituted with at least one fluorine atom
described above is preferably that having from 6 to 14 carbon atoms
and substituted with 1 to 9 fluorine atoms. Specific examples
thereof include pentafluorophenyl, 4-trifluoromethylphenyl,
heptafluoronaphthyl, nonafluoroanthryl, 4-fluorophenyl and
2,4-difluorophenyl groups.
[0085] The aralkyl group substituted with at least one fluorine
atom described above is preferably that having from 7 to 10 carbon
atoms and substituted with 1 to 15 fluorine atoms. Specific
examples thereof include pentafluorophenylmethyl,
pentafluorophenylethyl, perfluorobenzyl and perfluorophenethyl
groups.
[0086] The alkoxycarbonyl group substituted with at least one
fluorine atom described above is preferably that having from 2 to
13 carbon atoms and substituted with 1 to 25 fluorine atoms.
Specific examples thereof include trifluoromethoxycarbonyl,
pentafluoroethoxycarbonyl, pentafluoropenoxycarbonyl,
perfluorobutoxycarbonyl and perfluorooctyloxycarbonyl groups.
[0087] X.sup.- preferably represents a benzenesulfonic acid anion
substituted with a fluorine atom, and more preferably a
pentafluorobenzenesulfonic acid anion.
[0088] The alkylsulfonic acid, benzenesulfonic acid,
naphthalenesulfonic acid or anthracenesulfonic acid having the
fluorine-containing substituent may further be substituted with a
substituent, for example, a straight chain, branched or cyclic
alkoxy group, an acyl group, an acyloxy group, a sulfonyl group, a
sulfonyloxy group, a sulfonylamino group, an aryl group, an aralkyl
group or an alkoxycarbonyl group (the numbers of carbon atoms
included in these groups are same as those defined above
respectively), a halogen atom other than a fluorine atom, a hydroxy
group or a nitro group.
[0089] In the present invention, the compound of (A1) having a
reduction potential higher than -0.78 V, which is the reduction
potential of diphenyliodonium salt, can be used as the acid
generator. From the standpoint of stability, the compound of (A1)
having a reduction potential of not more than -0.5 V is preferably
used.
[0090] Specific examples of the compound of (A1) are set forth
below, but the present invention should not be construed as being
limited thereto. 111213141516
[0091] The content of compound of (A1) in the resist composition of
the present invention is suitably from 0.1 to 40% by weight,
preferably from 0.5 to 30% by weight, and more preferably from 1.0
to 25% by weight, based on the total solid content of the resist
composition.
[0092] <<(A2) Compound that Generates an Acid upon
Irradiation of an Actinic Ray or Radiation and has a Structure
Represented by any One of Formulae (I) to (III) (Hereinafter, also
Referred to as "Component (A2)" or "Compound of (A2)">>
[0093] The resist composition according to the present invention
may further contain the compound of (A2) as the acid generator.
[0094] In formulae (I) to (III), R.sub.1 to R.sub.37, which may be
the same or different, each represent a hydrogen atom, an alkyl
group, an alkoxy group, a hydroxy group, a halogen atom or a group
of --S--R.sub.38. R.sub.38 represents an alkyl group or an aryl
group.
[0095] The alkyl group represented by any one of R.sub.1 to
R.sub.38 may be any of straight chain, branched and cyclic alkyl
groups. The straight chain or branched alkyl group includes that
having from 1 to 4 carbon atoms, which may have a substituent, for
example, methyl, ethyl, propyl, n-butyl, sec-butyl or tert-butyl
group. The cyclic alkyl group includes that having from 3 to 8
carbon atoms, which may have a substituent, for example,
cyclopropyl, cyclopentyl or cyclohexyl group.
[0096] The alkoxy group represented by any one of R.sub.1 to
R.sub.37 may be any of straight chain, branched and cyclic alkoxy
groups. The straight chain or branched alkoxy group includes that
having from 1 to 8 carbon atoms, which may have a substituent, for
example, methoxy, ethoxy, hydroxyethoxy, propoxy, n-butoxy,
isobutoxy, sec-butoxy, tert-butoxy or octyloxy group. The cyclic
alkoxy group, which may have a substituent, includes, for example,
cyclopentyloxy and cyclohexyloxy groups.
[0097] The halogen atom represented by any one of R.sub.1 to
R.sub.37 includes, for example, fluorine, chlorine, bromine and
iodine atoms.
[0098] The aryl group represented by R.sub.38 includes that having
from 6 to 14 carbon atoms, which may have a substituent, for
example, phenyl, tolyl, methoxyphenyl or naphthyl group.
[0099] The substituents for the above groups preferably include an
alkyl group, an alkoxy group having from 1 to 4 carbon atoms, a
halogen atom (e.g., fluorine, chlorine or iodine atom), an aryl
group having from 6 to 10 carbon atoms, an alkenyl group having
from 2 to 6 carbon atoms, a cyano group, a hydroxy group, a carboxy
group, an alkoxycarbonyl group and a nitro group.
[0100] In formulae (I) to (III), X.sup.- represents an anion of an
alkylsulfonic acid, a benzenesulfonic acid, a naphthalenesulfonic
acid or an anthracenesulfonic acid, having at least one member
selected from a fluorine atom, an alkyl group substituted with at
least one fluorine atom, an alkoxy group substituted with at least
one fluorine atom, an acyl group substituted with at least one
fluorine atom, an acyloxy group substituted with at least one
fluorine atom, a sulfonyl group substituted with at least one
fluorine atom, a sulfonyloxy group substituted with at least one
fluorine atom, a sulfonylamino group substituted with at least one
fluorine atom, an aryl group substituted with at least one fluorine
atom, an aralkyl group substituted with at least one fluorine atom
and an alkoxycarbonyl group substituted with at least one fluorine
atom.
[0101] The alkyl group substituted with at least one fluorine atom
described above may be any of straight chain, branched and cyclic
alkyl groups and is preferably that having from 1 to 12 carbon
atoms and substituted with 1 to 25 fluorine atoms.
[0102] Specific examples thereof include trifluoromethyl,
pentafluoroethyl, 2,2,2-trifluoroethyl, heptafluoropropyl,
heptafluoroisopropyl, perfluorobutyl, perfluorooctyl,
perfluorododecyl and perfluorocyclohexyl groups. Among them, a
perfluoroalkyl group having from 1 to 4 carbon atoms fully
substituted with fluorine atoms is preferred. A perfluorobutyl
group is particularly preferred.
[0103] The alkoxy group substituted with at least one fluorine atom
described above may be any of straight chain, branched and cyclic
alkoxy groups and is preferably that having from 1 to 12 carbon
atoms and substituted with 1 to 25 fluorine atoms.
[0104] Specific examples thereof include trifluoromethoxy,
pentafluoroethoxy, heptafluoroisopropyloxy, perfluorobutoxy,
perfluorooctyloxy, perfluorododecyloxy and perfluorocyclohexyloxy
groups. Among them, a perfluoroalkoxy group having from 1 to 4
carbon atoms fully substituted with fluorine atoms is
preferred.
[0105] The acyl group substituted with at least one fluorine atom
described above is preferably that having from 2 to 12 carbon atoms
and substituted with 1 to 23 fluorine atoms. Specific examples
thereof include trifluoroacetyl, fluoroacetyl, pentafluoropropionyl
and pentafluorobenzoyl groups.
[0106] The acyloxy group substituted with at least one fluorine
atom described above is preferably that having from 2 to 12 carbon
atoms and substituted with 1 to 23 fluorine atoms. Specific
examples thereof include trifluoroacetoxy, fluoroacetoxy,
pentafluoropropionyloxy and pentafluorobenzoyloxy groups.
[0107] The sulfonyl group substituted with at least one fluorine
atom described above is preferably that having from 1 to 12 carbon
atoms and substituted with 1 to 25 fluorine atoms. Specific
examples thereof include trifluoromethanesulfonyl,
pentafluoroethanesulfonyl, perfluorobutanesulfonyl,
perfluorooctanesulfonyl, pentafluorobenzenesulfo- nyl and
4-trifluoromethylbenzenesulfonyl groups.
[0108] The sulfonyloxy group substituted with at least one fluorine
atom described above is preferably that having from 1 to 12 carbon
atoms and substituted with 1 to 25 fluorine atoms. Specific
examples thereof include trifluoromethanesulfonyloxy,
perfluorobutanesulfonyloxy and 4-trifluoromethylbenzenesulfonyloxy
groups.
[0109] The sulfonylamino group substituted with at least one
fluorine atom described above is preferably that having from 1 to
12 carbon atoms and substituted with 1 to 25 fluorine atoms.
Specific examples thereof include trifluoromethanesulfonylamino,
perfluorobutanesulfonylamino, perfluorooctanesulfonylamino and
pentafluorobenzenesulfonylamino groups.
[0110] The aryl group substituted with at least one fluorine atom
described above is preferably that having from 6 to 14 carbon atoms
and substituted with 1 to 9 fluorine atoms. Specific examples
thereof include pentafluorophenyl, 4-trifluoromethylphenyl,
heptafluoronaphthyl, nonafluoroanthryl, 4-fluorophenyl and
2,4-difluorophenyl groups.
[0111] The aralkyl group substituted with at least one fluorine
atom described above is preferably that having from 7 to 10 carbon
atoms and substituted with 1 to 15 fluorine atoms. Specific
examples thereof include pentafluorophenylmethyl,
pentafluorophenylethyl, perfluorobenzyl and perfluorophenethyl
groups.
[0112] The alkoxycarbonyl group substituted with at least one
fluorine atom described above is preferably that having from 2 to
13 carbon atoms and substituted with 1 to 25 fluorine atoms.
Specific examples thereof include trifluoromethoxycarbonyl,
pentafluoroethoxycarbonyl, pentafluoropenoxycarbonyl,
perfluorobutoxycarbonyl and perfluorooctyloxycarbonyl groups.
[0113] X.sup.- preferably represents a benzenesulfonic acid anion
substituted with a fluorine atom, and more preferably a
pentafluorobenzenesulfonic acid anion.
[0114] The alkylsulfonic acid, benzenesulfonic acid,
naphthalenesulfonic acid or anthracenesulfonic acid having the
fluorine-containing substituent may further be substituted with a
substituent, for example, a straight chain, branched or cyclic
alkoxy group, an acyl group, an acyloxy group, a sulfonyl group, a
sulfonyloxy group, a sulfonylamino group, an aryl group, an aralkyl
group or an alkoxycarbonyl group (the numbers of carbon atoms
included in these groups are same as those defined above
respectively), a halogen atom other than a fluorine atom, a hydroxy
group or a nitro group.
[0115] Specific examples of the compound represented by any one of
formulae (I) to (III) are set forth below, but the present
invention should not be construed as being limited thereto.
17181920212223
[0116] The compound represented by any one of formulae (I) and (II)
can be synthesized, for example, by a method comprising reacting an
aryl Grignard reagent, e.g., an aryl magnesium bromide with a
substituted or unsubstituted phenylsulfoxide and then subjecting
the resulting triaryl sulfonium halide to salt exchange with a
corresponding sulfonic acid, a method comprising condensing a
substituted or unsubstituted phenyl sulfoxide with a corresponding
aromatic compound in the presence of an acid catalyst, e.g.,
methanesulfonic acid/diphosphorus pentaoxide or aluminum chloride
and then subjecting the resulting condensate to salt exchange, or a
method comprising condensing a diaryl iodonium salt with a diaryl
sulfide in the presence of a catalyst, e.g., copper acetate and
then subjecting the resulting condensate to salt exchange.
[0117] The compound represented by formula (III) can be synthesized
by reacting an aromatic compound with a periodate and subjecting
the resulting iodonium salt to salt exchange with a corresponding
sulfonic acid.
[0118] The compound of (A1) and the compound of (A2) are used
together in a ratio described below in the present invention.
Specifically, the compounds are used ordinarily from 100/0 to
10/90, preferably from 90/10 to 30/70, more preferably from 80/20
to 40/60, in terms of a molar ratio of compound of (A1)/compound of
(A2).
[0119] <<(A3) Compound that Generates a Carboxylic Acid
Containing a Fluorine Atom upon Irradiation of an Actinic Ray or
Radiation (Hereinafter, also Referred to as "Compound of
(A3)">>
[0120] The resist composition according to the present invention
may further contain the compound of (A3) as the acid generator.
[0121] The carboxylic acid containing a fluorine atom includes, for
example, a fluorine-substituted aliphatic carboxylic acid and a
fluorine-substituted aromatic carboxylic acid.
[0122] The fluorine-substituted aliphatic carboxylic acid includes
a fluorine-substituted compound of an aliphatic carboxylic acid,
for example, acetic acid, propionic acid, n-butyric acid,
isobutyric acid, valeric acid, trimethylacetic acid, caproic acid,
heptanoic acid, caprylic acid, pelargonic acid, capric acid, lauric
acid, myristic acid, palmitic acid, stearic acid, undecanoic acid
or tridecanoic acid. The aliphatic carboxylic acid may have a
hydroxy group, an alkoxy group or a halogen atom other than a
fluorine atom as a substituent. The aliphatic carboxylic acid may
contain in its alicyclic chain a connecting group, for example, an
oxygen atom, a sulfur atom, a carbonyl group, an ester group or a
sulfonyl group.
[0123] Preferred examples of the fluorine-substituted aliphatic
carboxylic acid include those represented by the following
formula:
L-(CH.sub.2).sub.p(CF.sub.2).sub.q(CH.sub.2).sub.r--COOH
[0124] In the formula, L represents a hydrogen atom or a fluorine
atom, p and r each independently represent an integer of from 0 to
15, and q represents an integer of from 1 to 15. The hydrogen atom
or fluorine atom included in the alkyl chain in the formula may be
substituted with an alkyl group (preferably having from 1 to 5
carbon atoms) which may be substituted with a fluorine atom, an
alkoxy group (preferably having from 1 to 5 carbon atoms) which may
be substituted with a fluorine atom or a hydroxy group.
[0125] As the fluorine-substituted aliphatic carboxylic acid, a
fluorine-substituted compound of a saturated aliphatic carboxylic
acid having from 2 to 20 carbon atoms is preferred, and a
fluorine-substituted compound of a saturated aliphatic carboxylic
acid having from 4 to 20 carbon atoms is more preferred. By
controlling the number of carbon atoms in the aliphatic carboxylic
acid to 4 or more, diffusibility of the acid generated decreases,
and fluctuation of line width with the lapse of time from exposure
to post heating can be more restrained. Among them, a
fluorine-substituted compound of a straight chain or branched
saturated aliphatic carboxylic acid having from 4 to 18 carbon
atoms is preferably used.
[0126] As the fluorine-substituted aromatic carboxylic acid, a
fluorine-substituted compound of an aromatic carboxylic acid having
from 7 to 20 carbon atoms is preferred, a fluorine-substituted
compound of an aromatic carboxylic acid having from 7 to 15 carbon
atoms is more preferred, and an aromatic carboxylic acid having
from 7 to 11 carbon atoms is still more preferred. Specific
examples of the fluorine-substituted aromatic carboxylic acid
include a fluorine-substituted compound of an aromatic carboxylic
acid, for example, benzoic acid, a substituted benzoic acid,
naphthoic acid, a substituted naphthoic acid, anthracenecarboxylic
acid or a substituted anthracenecarboxylic acid (wherein the
substituent includes an alkyl group, an alkoxy group, a hydroxy
group, a halogen atom, an aryl group, an acyl group, an acyloxy
group, a nitro group, an alkylthio group and an arylthio group).
Among them, a fluorine-substituted compound of benzoic acid or
substituted benzoic acid is preferably used.
[0127] The aliphatic or aromatic carboxylic acid substituted with a
fluorine atom includes an aliphatic or aromatic carboxylic acid in
which at least one of the hydrogen atoms present in the skeleton
other than the carboxy group is substituted with a fluorine atom.
Particularly, an aliphatic or aromatic carboxylic acid in which all
of the hydrogen atoms present in the skeleton other than the
carboxy group are substituted with fluorine atoms (a perfluoro
saturated aliphatic carboxylic acid or a perfluoro aromatic
carboxylic acid) is preferred. By using such a perfluoro aliphatic
or aromatic carboxylic acid, the sensitivity is more improved.
[0128] Of the aliphatic carboxylic acid anions, an anion having a
fluorine atom on the a-carbon atom of carboxylic acid has a high
acid strength and tends to easily conduct salt exchange with a
carboxylic acid anion free from a fluorine atom. The perfluoro
aliphatic carboxylic acid anion has a higher acid strength.
[0129] Of the compounds of (A3), an onium salt compound (e.g., a
sulfonium salt or an iodonium salt) having as a counter anion, the
anion of aliphatic or aromatic carboxylic acid substituted with a
fluorine atom described above, an imidocarboxylate compound and a
nitrobenzyl ester compound each having a carboxylic acid ester
group are preferred.
[0130] More preferred examples of the compound of (A3) include
compounds represented by formulae (IF) to (IIIF) shown below.
[0131] By using such a compound, the sensitivity, resolution and
exposure margin are more improved. When the compound is irradiated
with an actinic ray or radiation, it generates a saturated
aliphatic or aromatic carboxylic acid substituted with at least one
fluorine atom, which corresponds to an anion represented by X.sup.-
in any one of formulae (IF) to (IIIF), whereby it functions as a
photo-acid generator. 24
[0132] In formulae (IF) to (IIIF), R.sub.1 to R.sub.37 each
independently represent a hydrogen atom, a straight chain, branched
or cyclic alkyl group, a straight chain, branched or cyclic alkoxy
group, a hydroxy group, a halogen atom or a group of --S--R.sub.38.
R.sub.38 represents a straight chain, branched or cyclic alkyl
group or an aryl group. X.sup.- represents an anion of an aliphatic
or aromatic carboxylic acid substituted with at least one fluorine
atom.
[0133] In any one of formulae (IF) to (IIIF), X.sup.- represents
preferably an anion of a perfluoro aliphatic carboxylic acid or a
perfluoro aromatic carboxylic acid, and more preferably an anion of
a fluorine-substituted alkylcarboxylic acid having not less than 4
carbon atoms.
[0134] The straight chain or branched alkyl group represented by
any one of R.sub.1 to R.sub.38 includes that having from 1 to 4
carbon atoms, which may have a substituent, for example, methyl,
ethyl, propyl, n-butyl, sec-butyl or tert-butyl group. The cyclic
alkyl group represented by any one of R.sub.1 to R.sub.38 includes
that having from 3 to 8 carbon atoms, which may have a substituent,
for example, cyclopropyl, cyclopentyl or cyclohexyl group.
[0135] The alkoxy group represented by any one of R.sub.1 to
R.sub.37 includes that having from 1 to 4 carbon atoms, which may
have a substituent, for example, methoxy, ethoxy, hydroxyethoxy,
propoxy, n-butoxy, isobutoxy, sec-butoxy or tert-butoxy group.
[0136] The halogen atom represented by any one of R.sub.1 to
R.sub.37 includes, for example, fluorine, chlorine, bromine and
iodine atoms.
[0137] The aryl group represented by R.sub.38 includes that having
from 6 to 14 carbon atoms, which may have a substituent, for
example, phenyl, tolyl, methoxyphenyl or naphthyl group.
[0138] The substituents for the above groups preferably include,
for example, an alkoxy group having from 1 to 4 carbon atoms, a
halogen atom (e.g., fluorine, chlorine or iodine atom), an aryl
group having from 6 to 10 carbon atoms, an alkenyl group having
from 2 to 6 carbon atoms, a cyano group, a hydroxy group, a carboxy
group, an alkoxycarbonyl group and a nitro group.
[0139] The iodonium compound or sulfonium compound represented by
any one of formulae (IF) to (IIIF) for use in the present invention
has as the counter anion represented by X.sup.-the anion of a
saturated aliphatic or aromatic carboxylic acid substituted with at
least one fluorine atom. The anion is an anion (--COO.sup.-) formed
by releasing the hydrogen atom of the saturated aliphatic or
aromatic carboxylic acid (--COOH).
[0140] Specific examples of the compound of (A3) are set forth
below, but the present invention should not be construed as being
limited thereto.
[0141] Specific examples (I-1f) to (I-36f) of the acid generator
represented by formula (IF): 25262728
[0142] Specific examples (II-1f) to (II-67f) of the acid generator
represented by formula (IIF): 29303132333435
[0143] Specific examples (III-1f) to (III-4f) of the acid generator
represented by formula (IIIF): 36
[0144] Specific examples (IV-1f) to (V-4f) of other acid generator:
37
[0145] The compound represented by formula (IF) can be synthesized
by reacting an aromatic compound with a periodate and subjecting
the resulting iodonium salt to salt exchange with a corresponding
carboxylic acid.
[0146] The compound represented by any one of formulae (IIF) and
(IIIF) can be synthesized, for example, by a method comprising
reacting an aryl Grignard reagent, e.g., an aryl magnesium bromide
with a substituted or unsubstituted phenylsulfoxide and then
subjecting the resulting triaryl sulfonium halide to salt exchange
with a corresponding carboxylic acid, a method comprising
condensing a substituted or unsubstituted phenyl sulfoxide with a
corresponding aromatic compound in the presence of an acid
catalyst, e.g., methanesulfonic acid/diphosphorus pentaoxide or
aluminum chloride and then subjecting the resulting condensate to
salt exchange, or a method comprising condensing a diaryl iodonium
salt with a diaryl sulfide in the presence of a catalyst, e.g.,
copper acetate and then subjecting the resulting condensate to salt
exchange.
[0147] The salt exchange can be conducted by introducing once into
a halide, followed by converting to a carboxylate using a silver
reagent, e.g., silver oxide, or by using an ion exchange resin. For
the salt exchange, a carboxylic acid or carboxylate commercially
available or obtained by hydrolysis of a commercially available
carboxylic acid halide can be employed.
[0148] The fluorine-substituted carboxylic acid as the anion
portion is preferably that derived from a fluoro-aliphatic compound
produced by a telomerization method (also referred to as a telomer
method) or an origomerization method (also referred to as an
origomer method). Methods for the production of fluoro-aliphatic
compound are described, for example, in Nobuo Ishikawa ed.,
Fusso-Kagobutsu no Gosei to Kino (Synthesis and Function of
Fluorine Compounds), pages 117 to 118, CMC Publishing Co., Ltd.
(1987) and Milos Hudlicky and Attila E. Pavlath ed., Chemistry of
Organic Fluorine Compounds II, Monograph 187, pages 747 to 752,
American Chemical Society (1995). The telomerization method
comprises a radical polymerization of a fluorine-containing vinyl
compound, e.g., tetrafluoroethylene using an alkyl halide having a
large chain transfer constant, e.g., an iodide, as a telogen to
synthesize a telomer. In the synthesis according to the telomer
method, a mixture of plural compounds having a carbon chain length
different from each other are obtained, and the mixture may be used
as it is or after purification.
[0149] The compound of (A1) and the compound of (A3) are used
together in a ratio described below in the present invention.
Specifically, the compounds are used ordinarily from 100/0 to
10/90, preferably from 90/10 to 30/70, more preferably from 80/20
to 40/60, in terms of a molar ratio of compound of (A1)/compound of
(A3).
[0150] <<(A4) Compound that Generates a Carboxylic Acid Free
from a Fluorine Atom upon Irradiation of an Actinic Ray or
Radiation (Hereinafter, also Referred to as "Compound of
(A4)">>
[0151] The resist composition according to the present invention
may further contain the compound of (A4) as the acid generator.
[0152] The compound of (A4) includes, for example, compounds
represented by the following formulae (AI) to (AV): 38
[0153] In the above formulae, R.sub.301 to R.sub.337 each
independently represent a hydrogen atom, a straight chain, branched
or cyclic alkyl group, a straight chain, branched or cyclic alkoxy
group, a hydroxy group, a halogen atom or a group of --S--R.sub.0.
R.sub.0 represents a straight chain, branched or cyclic alkyl group
or an aryl group.
[0154] R.sub.a and R.sub.b each independently represent a hydrogen
atom, a nitro group, a halogen atom, an alkyl group which may have
a substituent or an alkoxy group which may have a substituent.
R.sub.c and R.sub.d each independently represent a halogen atom, an
alkyl group which may have a substituent or an aryl group which may
have a substituent. Alternatively, R.sub.c and R.sub.d may be
combined with each other to form an aromatic ring or a monocyclic
or polycyclic aliphatic hydrocarbon ring (the ring may contain an
oxygen atom or a nitrogen atom) . Y.sub.1 and Y.sub.2 each
represent a carbon atom, and the Y.sub.1--Y.sub.2 bond may be a
single bond or a double bond. X.sup.- represents an anion of at
least one of carboxylic acid compounds represented by formulae
shown below. X.sub.1 and X.sub.2 each independently represent an
ester group formed at the carboxy group of at least one of the
carboxylic acid compounds represented by formulae shown below.
39
[0155] In the above formulae, R.sub.338 represents a straight
chain, branched or cyclic alkyl group having from 1 to 30 carbon
atoms (wherein the alkyl group may contain an oxygen atom or a
nitrogen atom in the chain thereof), a straight chain, branched or
cyclic alkenyl group having from 2 to 20 carbon atoms, a straight
chain, branched or cyclic alkynyl group having from 2 to 20 carbon
atoms, a straight chain, branched or cyclic alkoxy group having
from 1 to 20 carbon atoms, the above alkyl group in which at least
a part of the hydrogen atoms is substituted with a halogen atom
and/or a hydroxy group, the above alkenyl group in which at least a
part of the hydrogen atoms is substituted with a halogen atom
and/or a hydroxy group or a substituted or unsubstituted aryl group
having from 6 to 20 carbon atoms. Examples of the substituent for
the aryl group include an alkyl group, a nitro group, a hydroxy
group, an alkoxy group, an acyl group, an alkoxycarbonyl group and
a halogen atom.
[0156] R.sub.339 represents a single bond, a straight chain,
branched or cyclic alkylene group having from 1 to 20 carbon atoms
(wherein the alkylene group may contain an oxygen atom or a
nitrogen atom in the chain thereof), a straight chain, branched or
cyclic alkenylene group having from 2 to 20 carbon atoms, the above
alkylene group in which at least a part of the hydrogen atoms is
substituted with a halogen atom and/or a hydroxy group, the above
alkenylene group in which at least a part of the hydrogen atoms is
substituted with a halogen atom and/or a hydroxy group or an
alkoxyalkylene group having from 2 to 20 carbon atoms. The plural
R.sub.338's and R.sub.339's may be the same or different from each
other.
[0157] R.sub.340 represents a hydroxy group or a halogen atom. The
plural R.sub.340's may be the same or different from each other. m,
n, p and q each independently represent an integer of from 0 to 3,
provided that m+n.ltoreq.5 and p+q.ltoreq.5. z represents 0 or
1.
[0158] In formulae (AI) to (AV), the straight chain or branched
alkyl group represented by any one of R.sub.301 to R.sub.337,
R.sub.a, R.sub.b, R.sub.c, R.sub.d and R.sub.0 includes that having
from 1 to 4 carbon atoms, which may have a substituent, for
example, methyl, ethyl, propyl, n-butyl, sec-butyl or tert-butyl
group. The cycloalkyl group includes that having from 3 to 8 carbon
atoms, which may have a substituent, for example, cyclopropyl,
cyclopentyl or cyclohexyl group.
[0159] The alkoxy group represented by any one of R.sub.301 to
R.sub.337, R.sub.a and R.sub.b includes that having from 1 to 4
carbon atoms, which may have a substituent, for example, methoxy,
ethoxy, hydroxyethoxy, propoxy, n-butoxy, isobutoxy, sec-butoxy or
tert-butoxy group.
[0160] The halogen atom represented by any one of R.sub.301 to
R.sub.337, R.sub.a, R.sub.b, R.sub.c and R.sub.d includes, for
example, fluorine, chlorine, bromine and iodine atoms.
[0161] The aryl group represented by any one of R.sub.0, R.sub.c
and R.sub.d includes that having from 6 to 14 carbon atoms, which
may have a substituent, for example, phenyl, tolyl, methoxyphenyl
or naphthyl group.
[0162] The substituents for the above groups preferably includes an
alkoxy group having from 1 to 4 carbon atoms, a halogen atom (e.g.,
fluorine, chlorine or iodine atom), an aryl group having from 6 to
10 carbon atoms, an alkenyl group having from 2 to 6 carbon atoms,
a cyano group, a hydroxy group, a carboxy group, an alkoxycarbonyl
group and a nitro group.
[0163] The aromatic ring, or monocyclic or polycyclic aliphatic
hydrocarbon ring (the ring may contain an oxygen atom or a nitrogen
atom) formed by combining R.sub.c and R.sub.d includes, for
example, benzene, naphthalene, cyclohexane, norbornene and
oxabicyclo structures.
[0164] The sulfonium or iodonium compound represented by any one of
formulae (AI) to (AIII) for use in the present invention includes
as the counter anion represented by X.sup.-, an anion (--COO.sup.-)
of the carboxy group (--COOH) of at least one of the carboxylic
compounds represented by any one of formulae (C1) to (C10)
described above.
[0165] The compound represented by any one of formulae (AIV) to
(AV) for use in the present invention includes as the substituent
X.sub.1 or X.sub.2, an ester group (--COO--) formed from the
carboxy group (--COOH) of at least one of the carboxylic compounds
represented by any one of formulae (C1) to (C10) described
above.
[0166] The straight chain, branched or cyclic alkyl group having
from 1 to 30 carbon atoms (wherein the alkyl group may contain an
oxygen atom or a nitrogen atom in the chain thereof) represented by
R.sub.338 includes, for example, methyl, ethyl, propyl, butyl,
pentyl, hexyl, cyclohexyl, dodecyl, 1-ethoxyethyl and adamantyl
groups.
[0167] The straight chain, branched or cyclic alkenyl group having
from 2 to 20 carbon atoms includes, for example, ethenyl, propenyl,
isopropenyl and cyclohexenyl groups.
[0168] The straight chain, branched or cyclic alkynyl group having
from 2 to 20 carbon atoms includes, for example, ethynyl and
propynyl groups.
[0169] The straight chain, branched or cyclic alkoxy group having
from 1 to 20 carbon atoms includes, for example, methoxy, ethoxy,
propyloxy, butoxy, cyclohexyloxy, isobutoxy and dodecyloxy
groups.
[0170] The substituted or unsubstituted aryl group having from 6 to
20 carbon atoms includes, for example, phenyl, naphthyl and anthryl
groups.
[0171] The substituent for the aryl group includes, for example, an
alkyl group, a nitro group, a hydroxy group, an alkoxy group, an
acyl group, an alkoxycarbonyl group and a halogen atom.
[0172] The straight chain, branched or cyclic alkylene group having
from 1 to 20 carbon atoms (wherein the alkylene group may contain
an oxygen atom or a nitrogen atom in the chain thereof) represented
by R.sub.339 includes, for example, methylene, ethylene, propylene,
butylene, isobutylene, ethoxyethylene and cyclohexylene groups.
[0173] The straight chain, branched or cyclic alkenylene group
having from 2 to 20 carbon atoms includes, for example, vinylene
and allylene groups.
[0174] Specific examples of the compound of (A4) are set forth
below, but the present invention should not be construed as being
limited thereto. 404142434445464748495051525354555657
[0175] The compound of (A1) and the compound of (A4) are used
together in a ratio described below in the present invention.
Specifically, the compounds are used ordinarily from 100/0 to
10/90, preferably from 90/10 to 30/70, more preferably from 80/20
to 40/60, in terms of a molar ratio of compound of (A1)/compound of
(A4).
[0176] <<Other Compounds that Generate an Acid upon
Irradiation of an Actinic Ray or Radiation>>
[0177] In the present invention, a compound that generates an acid
upon irradiation of an actinic ray or radiation other than the
compound of (A1), the compound of (A2), the compound of (A3) and
the compound of (A4) described above may be further used
together.
[0178] A molar ratio of the total amount of compound of (A1),
compound of (A2), compound of (A3) and compound of (A4) according
to the present invention to the other compound that generates an
acid upon irradiation of an actinic ray or radiation used together
therewith is ordinarily from 100/0 to 10/90, preferably from 98/2
to 40/60, and more preferably from 95/5 to 50/50.
[0179] Such a compound that generates an acid upon irradiation of
an actinic ray or radiation used together with the acid generators
according to the present invention can be appropriately selected
from photoinitiators for cationic polymerization, photoinitiators
for photo-radical polymerization, photo-achromatic agents for dyes,
photo-discoloring agents, compounds capable of generating an acid
upon known light used for microresists, and mixtures thereof.
[0180] Specific examples of such compounds include diazonium salts
as described, e.g., in S. I. Schlesinger, Photogr. Sci. Eng., 18,
387 (1974) and T. S. Bal et al., Polymer, 21, 423 (1980); onium
salts, for example, ammonium salts as described, e.g., in U.S. Pat.
Nos. 4,069,055, 4,069,056 and Re 27,992 and JP-A-3-140140,
phosphonium salts as described, e.g., in D. C. Necker et al.,
Macromolecules, 17, 2468 (1984), C. S. Wen et al., Teh. Proc. Conf.
Rad. Curing ASIA, p. 478, Tokyo (Oct. 1988) and U.S. Pat. Nos.
4,069,055 and 4,069,056, iodonium salts as described, e.g., in J.
V. Crivello et al., Macromolecules, 10(6), 1307(1977), Chem. &
Eng. News, Nov. 28, p. 31 (1988), European Patents 104,143, 339,049
and 410,201, JP-A-2-150848 and JP-A-2-296514, sulfonium salts as
described, e.g., in J. V. Crivello et al., Polymer J., 17, 73
(1985), J. V. Crivello et al., J. Org. Chem., 43, 3055 (1978), W.
R. Watt et al., J. Polymer Sci., Polymer Chem. Ed., 22, 1789
(1984), J. V. Crivello et al., Polymer Bull., 14, 279 (1985), J. V.
Crivello et al., Macromolecules, 14(5), 1141 (1981), J. V. Crivello
et al., J. Polymer Sci., Polymer Chem. Ed., 17, 2877 (1979),
European Patents 370,693, 161,811, 410,201, 339,049, 233,567,
297,443 and 297,442, U.S. Pat. Nos. 3,902,114, 4,933,377,
4,760,013, 4,734,444 and 2,883,827, German Patents 2,904,626,
3,604,580 and 3,604,581, selenonium salts as described, e.g., in J.
V. Crivello et al., Macromolecules, 10(6), 1307 (1977) and J. V.
Crivello et al., J. Polymer Sci., Polymer Chem. Ed., 17, 1047
(1979), and arsonium salts as described, e.g., in C. S. Wen et al.,
Teh. Proc. Conf. Rad. Curing ASIA, p. 478, Tokyo (Oct., 1988);
organic halogen compounds as described, e.g., in U.S. Pat. No.
3,905,815, JP-B-46-4605, JP-A-48-36281, JP-A-55-32070,
JP-A-60-239736, JP-A-61-169835, JP-A-61-169837, JP-A-62-58241,
JP-A-62-212401, JP-A-63-70243 and JP-A-63-298339; organic
metal/organic halogen compounds as described, e.g., in K. Meier et
al., J. Rad. Curing, 13(4), 26(1986), T. P. Gill et al., Inorg.
Chem., 19, 3007 (1980), D. Astruc, Acc. Chem. Res., 19(12), 377
(1986) and JP-A-2-161445; photo-acid generators having an
o-nitrobenzyl type protective group as described, e.g., in S.
Hayase et al., J. Polymer Sci., 25, 753 (1987), E. Reichmanis et
al., J. Polymer Sci., Polymer Chem. Ed., 23, 1 (1985), Q. Q. Zhu et
al., J. Photochem., 36, 85, 39, 317 (1987), B. Amit et al.,
Tetrahedron Lett., (24) 2205 (1973), D. H. R. Barton et al., J.
Chem. Soc., 3571 (1965), P. M. Collins et al., J. Chem. Soc.,
Perkin I, 1695 (1975), M. Rudinstein et al., Tetrahedron Lett.,
(17), 1445 (1975), J. W. Walker et al., J. Am. Chem. Soc., 110,
7170 (1988), S. C. Busman et al., J. imaging Technol., 11(4), 191
(1985), H. M. Houlihan et al., Macromolecules, 21, 2001 (1988), P.
M. Collins et al., J. Chem. Soc., Chem. Commun., 532 (1972), S.
Hayase et al., Macromolecules, 18, 1799 (1985), E. Reichmanis et
al., J. Electrochem. Soc., Solid State Sci. Technol., 130(6), F. M.
Houlihan et al., Macromolecules, 21, 2001 (1988), European Patents
290,750, 046,083, 156,535, 271,851 and 388,343, U.S. Pat. Nos.
3,901,710 and 4,181,531, JP-A-60-198538 and JP-A-53-133022;
compounds generating a sulfonic acid upon photolysis, as typified
by iminosulfonates, as described, e.g., in M. Tunooka et al.,
Polymer Preprints Japan, 35(8), G. Berner et al., J. Rad. Curing,
13(4), W. J. Mijs et al., Coating Technol., 55(697), 45(1983),
Akzo, H. Adachi et al., Polymer Preprints Japan, 37(3), European
Patents 199,672, 084,515, 044,115, 618,564 and 101,122, U.S. Pat.
Nos. 4,371,605 and 4,431,774, JP-A-64-18143, JP-A-2-245756 and
JP-A-3-140109; and disulfone compounds as described, e.g., in
JP-A-61-166544.
[0181] Also, polymer compounds in which a group or compound capable
of generating an acid upon exposure to light is introduced into the
main chain or side chain thereof, for example, compounds as
described, e.g., in M. E. Woodhouse et al., J. Am. Chem. Soc., 104,
5586(1982), S. P. Pappas et al., J. Imaging Sci., 30(5), 218(1986),
S. Kondo et al., Makromol. Chem., Rapid Commun., 9, 625(1988), Y.
Yamada et al., Makromol. Chem., 152, 153, 163 (1972), J. V.
Crivello et al., J. Polymer Sci., Polymer Chem. Ed., 17,
3845(1979), U.S. Pat. No. 3,849,137, German Patent 3,914,407,
JP-A-63-26653, JP-A-55-164824, JP-A-62-69263, JP-A-63-146038,
JP-A-63-163452, JP-A-62-153853 and JP-A-63-146029 can be used.
[0182] Further, compounds capable of generating an acid upon
exposure to light as described, e.g., in V. N. R. Pillai,
Synthesis, (1), 1 (1980), A. Abad et al., Tetrahedron Lett., (47)
4555 (1971), D. H. R. Barton et al., J. Chem. Soc., (C), 329
(1970), U.S. Pat. No. 3,779,778 and European Patent 126,712 can
also be used.
[0183] <<(BP) Polymer that is Insoluble or Hardly Soluble in
an Aqueous Alkali Solution but Becomes Soluble in the Aqueous
Alkali Solution by the Action of an Acid (Hereinafter, also
Referred to as "Component (BP)">>
[0184] The component (BP) for use in the positive resist
composition of the present invention includes a resin having a
group decomposable with an acid in the main chain or side chain
thereof, or in both the main chain and side chain thereof. A resin
having a group decomposable with an acid in the side chain thereof
is more preferred.
[0185] Preferred examples of the group decomposable with an acid
include a group represented by --COOA.sup.0 and a group represented
by --O--B.sup.0.
[0186] In the above formulae, A.sup.0 represents --C(R.sup.01)
(R.sup.02) (R.sup.03), --Si(R.sup.01) (R.sup.02) (R.sup.03) or
--C(R.sup.04) (R.sup.05) --O--R.sup.06. B.sup.0 represents -A.sup.0
or --CO--O-A.sup.0. R.sup.01 to R.sup.06, which may be the same or
different, each represent an alkyl group which may have a
substituent, a cycloalkyl group which may have a substituent, an
alkenyl group which may have a substituent, an aralkyl group which
may have a substituent or an aryl group which may have a
substituent.
[0187] Preferred examples of the group decomposable with an acid
include a silyl ether group, a cumyl ester group, an acetal group,
a tetrahydropyranyl ether group, an enol ether group, an enol ester
group, a tertiary alkyl ether group, a tertiary alkyl ester group
and a tertiary alkylcarbonate group. More preferred examples
thereof include a tertiary alkyl ester group, a tertiary
alkylcarbonate group, a cumyl ester group, an acetal group and a
tetrahydropyranyl ether group. Particularly, tert-butoxycarbonyl
group is preferred.
[0188] In a case wherein the group decomposable with an acid is
bonded as a side chain, a parent resin is an alkali-soluble resin
having an --OH group or a --COOH group in the side chain. Examples
of the parent resin include alkali-soluble resins described
hereinafter.
[0189] An alkali-dissolution rate of the alkali-soluble resin is
preferably not less than 170 angstroms/sec, and more preferably not
less than 330 angstroms/sec, when measured in a 0.261 N aqueous
solution of tetramethylammonium hydroxide (TMAH) at 23.degree.
C.
[0190] From the standpoint of alkali-dissolution rate, preferred
examples of the alkali-soluble resin include a poly(o-, m-, or
p-hydroxystyrene), a copolymer of o-, m-, or p-hydroxystyrene, a
hydrogenated poly(hydroxystyrene), a halogen- or alkyl-substituted
poly(hydroxystyrene), a partially O-alkylated or O-acylated
poly(hydroxystyrene), a styrene-hydroxystyrene copolymer, an
.alpha.-methylstyrene-hydroxystyrene copolymer and a hydrogenated
novolac resin.
[0191] A resin having a structural unit containing a group
represented by formula (X1) or (X2) described above is also
referred as the component (BP).
[0192] In formula (X1), R.sub.1b and R.sub.2b, which may be the
same or different, each represent a hydrogen atom or an alkyl
group. R.sub.3b and R.sub.4b, which may be the same or different,
each represent a hydrogen atom, an alkyl group which may have a
substituent or a cycloalkyl group which may have a substituent.
R.sub.5b represents an alkyl group which may have a substituent, a
cycloalkyl group which may have a substituent, an aryl group which
may have a substituent or an aralkyl group which may have a
substituent. m represents an integer of from 0 to 20, and n
represents an integer of from 0 to 5.
[0193] In formula (X2), R.sub.6b and R.sub.7b, which may be the
same or different, each represent a hydrogen atom or an alkyl
group. W represents a divalent organic group. R.sub.8b represents
an alkyl group which may have a substituent, a cycloalkyl group
which may have a substituent, an aryl group which may have a
substituent or an aralkyl group which may have a substituent.
[0194] The alkyl group represented by any one of R.sup.01 to
R.sup.06 and R.sub.1b to R.sub.8b may be a straight chain or
branched alkyl group, and preferably includes that having from 1 to
4 carbon atoms, which may have a substituent, for example, methyl,
ethyl, propyl, n-butyl, sec-butyl or tert-butyl group.
[0195] The cycloalkyl group represented by any one of R.sup.01 to
R.sup.06, R.sub.3b to R.sub.5b and R.sub.8b preferably includes
that having from 3 to 8 carbon atoms, which may have a substituent,
for example, cyclopropyl, cyclopentyl or cyclohexyl group.
[0196] The alkenyl group represented by any one of R.sup.01 to
R.sup.06 preferably includes that having from 2 to 8 carbon atoms,
which may have a substituent, for example, vinyl, allyl, butenyl or
cyclohexenyl group.
[0197] The aralkyl group represented by any one of R.sup.01 to
R.sup.06, R.sub.5b and R.sub.8b preferably includes that having
from 7 to 12 carbon atoms, which may have a substituent, for
example, benzyl, phenethyl or naphthylmethyl group.
[0198] The aryl group represented by any one of R.sup.01 to
R.sup.06, R.sub.5b and R.sub.8b preferably includes that having
from 6 to 15 carbon atoms, which may have a substituent, for
example, phenyl, tolyl, naphthyl or anthryl group.
[0199] The substituent for the alkyl, cycloalkyl, alkenyl, aralkyl
or aryl group described above include, for example, a carboxy
group, an acyloxy group, a cyano group, an aryl group, an alkyl
group, a cycloalkyl group, a halogen atom, a hydroxy group, an
alkoxy group, an acetylamido group, an alkoxycarbonyl group and an
acyl group.
[0200] The divalent organic group represented by W preferably
includes a straight chain, branched or cyclic alkylene group which
may have a substituent, an arylene group which may have a
substituent, a heteroarylene group which may have a substituent, an
aralkylene group which may have a substituent, --S--,
--C(.dbd.O)--, --N(R.sub.4c)--, --SO--, --SO.sub.2--, --CO.sub.2--,
--N(R.sub.4c)SO.sub.2-- and a divalent group formed by combination
of two or more of these groups. R.sub.4c, represents a hydrogen
atom or an alkyl group (which has the same meaning as the alkyl
group represented by R.sup.01 described above).
[0201] The component (BP) for use in the present invention can be
obtained by reacting an alkali-soluble resin with a precursor of
the group decomposable with an acid, or by copolymerizing a monomer
for forming an alkali-soluble resin, which has the group
decomposable with an acid, with any of various monomers, as
described, for example, in European Patent 254,853, JP-A-2-25850,
JP-A-3-223860 and JP-A-4-251259.
[0202] Specific examples of the component (BP) for use in the
present invention are set forth below, but the present invention
should not be construed as being limited thereto.
585960616263646566676869
[0203] A ratio of content of the group decomposable with an acid in
the resin is indicated by a formula of B/(B+S) wherein B represents
a number of the group decomposable with an acid and S represents a
number of an alkali-soluble group that is not protected by the
group decomposable with an acid. The ratio of content is preferably
from 0.01 to 0.7, more preferably from 0.05 to 0.50, and still more
preferably from 0.05 to 0.40. The ratio of content of more than 0.7
is disadvantageous in view of film shrinking after PEB, adhesion
failure to a substrate or occurrence of scam. On the other hand,
the ratio of content of less than 0.01 is also not preferred, since
a remarkable standing wave effect on the sidewall of pattern may
occur in some cases.
[0204] The weight average molecular weight (Mw) of the component
(BP) is preferably in a range of from 2,000 to 200,000. If it is
less than 2,000, decrease in a film thickness of the unexposed area
after development is large and on the other hand, if it exceeds
200,000, a dissolution rate of the alkali-soluble resin per se to
alkali decreases, resulting in lowering sensitivity. The weight
average molecular weight is more preferably in a range of from
5,000 to 100,000, and still more preferably in a range of from
8,000 to 50,000.
[0205] The molecular weight distribution (Mw/Mn) is preferably from
1.0 to 4.0, more preferably from 1.0 to 2.0, and particularly
preferably from 1.0 to 1.6.
[0206] The weight average molecular weight is expressed using a
value determined by gel permeation chromatography and calculated in
terms of polystyrene.
[0207] Two or more of the polymers of component (BP) may be used in
the positive resist composition of the present invention.
[0208] The amount of the polymer of component (BP) is ordinarily
from 70 to 98% by weight, and preferably from 80 to 96% by weight,
based on the solid content of the positive resist composition of
the present invention.
[0209] <<(BN) Alkali-Soluble Resin (Hereinafter, also
Referred to as "Component (BN)" or "Resin of (BN)">>
[0210] The alkali-soluble resin for use in the negative resist
composition of the present invention includes polymers having a
phenol skeleton, which have hitherto been disclosed for negative
chemical amplification resists, for example, phenol novolac resins,
polyvinylphenol resins, copolymers having a structural unit derived
from vinylphenol and resins obtained by protecting or modifying a
part of polyvinylphenol resin.
[0211] The resin of component (BN) includes preferably a resin
containing a repeating unit represented by the following formula
(a): 70
[0212] In formula (a), R.sub.1 represents a hydrogen atom, a
halogen atom, a cyano group, an alkyl group which may have a
substituent or a haloalkyl group which may have a substituent.
R.sub.2 represents a hydrogen atom, an alkyl group which may have a
substituent, a cycloalkyl group which may have a substituent, an
aryl group which may have a substituent, an aralkyl group which may
have a substituent or an acyl group which may have a substituent.
R.sub.3 and R.sub.4, which may be the same or different, each
represent a hydrogen atom, a halogen atom, a cyano group, an alkyl
group which may have a substituent, a cycloalkyl group which may
have a substituent, an alkenyl group which may have a substituent,
an aralkyl group which may have a substituent or an aryl group
which may have a substituent.
[0213] A represents a single bond, an alkylene group which may have
a substituent, an alkenylene group which may have a substituent, a
cycloalkylene group which may have a substituent, an arylene group
which may have a substituent, --O--, --SO.sub.2--,
--O--CO--R.sub.5--, --CO--O--R.sub.6-- or
--CO--N(R.sub.7)--R.sub.8--.
[0214] R.sub.5, R.sub.6 and R.sub.8, which may be the same or
different, each represent a single bond, an alkylene group which
may have a substituent, an alkenylene group which may have a
substituent, a cycloalkylene group which may have a substituent, an
arylene group which may have a substituent, a divalent group formed
by combining the above-described alkylene, alkenylene,
cycloalkylene or arylene group and at least one member selected
from an ether structure, an ester structure, an amido structure, a
urethane structure and a ureido structure.
[0215] R.sub.7 represents a hydrogen atom, an alkyl group which may
have a substituent, a cycloalkyl group which may have a
substituent, an aralkyl group which may have a substituent or an
aryl group which may have a substituent.
[0216] n represents an integer of from 1 to 3. Alternatively,
plural R.sub.2's, R.sub.2 and R.sub.3 or R.sub.2 and R.sub.4 may be
combined with each other to form a ring.
[0217] A phenol resin containing the repeating structural unit
represented by formula (a) described above is more preferably
used.
[0218] The alkyl group represented by any one of R.sub.1 to R.sub.4
and R.sub.7 preferably includes an alkyl group having from 1 to 8
carbon atoms, specifically, methyl, ethyl, propyl, n-butyl,
sec-butyl, hexyl, 2-ethylhexyl and octyl groups. The cycloalkyl
group represented by any one of R.sub.2 to R.sub.4 and R.sub.7 may
be monocyclic or polycyclic. The monocyclic cycloalkyl group
preferably includes that having from 3 to 8 carbon atoms,
specifically, cyclopropyl, cyclopentyl and cyclohexyl groups. The
polycyclic cycloalkyl group preferably includes adamantyl,
norbornyl, isobornyl, dicyclopentyl, .alpha.-pinenyl and
tricyclodecanyl groups.
[0219] The alkenyl group represented by any one of R.sub.3 and
R.sub.4 preferably includes an alkenyl group having from 2 to 8
carbon atoms, specifically, vinyl, allyl, butenyl and cyclohexenyl
groups.
[0220] The aryl group represented by any one of R.sub.2 to R.sub.4
and R.sub.7 preferably includes an aryl group having from 6 to 15
carbon atoms, specifically, phenyl, tolyl, dimethylphenyl,
2,4,6-trimethylphenyl, naphthyl and anthryl groups.
[0221] The aralkyl group represented by any one of R.sub.2 to
R.sub.4 and R.sub.7 preferably includes an aralkyl group having
from 7 to 12 carbon atoms, specifically, benzyl, phenethyl and
naphthylmethyl groups.
[0222] The haloalkyl group represented by R.sub.1 preferably
includes a haloalkyl group having from 1 to 4 carbon atoms,
specifically, chloromethyl, chloroethyl, chloropropyl, chlorobutyl,
bromomethyl and bromoethyl groups.
[0223] The acyl group represented by R.sub.2 preferably includes an
acyl group having from 1 to 8 carbon atoms, specifically, formyl,
acetyl, propanoyl, butanoyl, pivaloyl and benzoyl groups.
[0224] The alkylene group represented by any one of A, R.sub.5,
R.sub.6 and R.sub.8 preferably includes an alkylene group having
from 1 to 8 carbon atoms, which may have a substituent,
specifically, methylene, ethylene, propylene, butylene, hexylene
and octylene groups.
[0225] The alkenylene group represented by any one of A, R.sub.5,
R.sub.6 and R.sub.8 preferably includes an alkenylene group having
from 2 to 6 carbon atoms, which may have a substituent,
specifically, ethenylene, propenylene and butenylene groups.
[0226] The cycloalkylene group represented by any one of A,
R.sub.5, R.sub.6 and R.sub.8 preferably includes a cycloalkylene
group having from 5 to 8 carbon atoms, which may have a
substituent, specifically, cyclopentylene and cyclohexylene
groups.
[0227] The arylene group represented by any one of A, R.sub.5,
R.sub.6 and R.sub.8 preferably includes an arylene group having
from 6 to 12 carbon atoms, which may have a substituent,
specifically, phenylene, tolylene and naphthylene groups.
[0228] The substituents for the above-described groups include a
group having an active hydrogen, for example, an amino group, an
amido group, a ureido group, a urethane group, a hydroxy group or a
carboxy group, a halogen atom (e.g., fluorine, chlorine, bromine or
iodine atom), an alkoxy group (e.g., methoxy, ethoxy, propoxy or
butoxy group), a thioether group, an acyl group (e.g., acetyl,
propanoyl or benzoyl group), an acyloxy group (e.g., acetoxy,
propanoyloxy or benzoyloxy group), an alkoxycarbonyl group (e.g.,
methoxycarbonyl, ethoxycarbonyl or propoxycarbonyl group), a cyano
group and a nitro group. Particularly, a group having an active
hydrogen, for example, an amino group, a hydroxy group or a carboxy
group is preferred.
[0229] The ring formed by combining plural R.sub.2's, R.sub.2 and
R.sub.3 or R.sub.2 and R.sub.4 with each other includes 4-membered
to 7-membered rings containing the oxygen atom, for example,
benzofuran, benzodioxonol or benzopyran ring.
[0230] The resin of (BN) for use in the present invention may be a
resin composed of the repeating structural unit represented by
formula (a) alone. For the purpose of further improving performance
of the negative resist composition of the present invention, the
resin of (BN) may be a copolymer containing the repeating
structural unit represented by formula (a) and repeating units
derived from one or more other polymerizable monomers.
[0231] The copolymerizable monomers which can be used in the
present invention include, for example, compounds having one
addition-polymerizable unsaturated bond selected from acrylic acid
esters, acrylamides, methacrylic acid esters, methacrylamides,
allyl compounds, vinyl ethers, vinyl esters, styrenes and crotonic
acid esters.
[0232] Among the monomers, monomers improving the solubility in
alkali, for example, a monomer having a carboxy group, e.g.,
carboxystyrene, N-(carboxyphenyl)acrylamide or
N-(carboxyphenyl)methacrylamide, or maleimide is preferred as the
copolymerization component.
[0233] The content of other monomers in the resin is preferably 50%
by mole or less, and more preferably 30% by mole or less, based on
the total repeating units of the resin.
[0234] Specific examples of the resin having the repeating
structural unit represented by formula (a) are set forth below, but
the present invention should not be construed as being limited
thereto. 717273747576777879808182838485868788899091929394
[0235] In the specific examples described above, n represents a
positive integer. x, y and z each represent a molar ratio of each
repeating unit. In the resin composed of two components, x and y
are used in the range of x=10 to 95 and y=5 to 90, and preferably
x=40 to 90 and y=10 to 60. In the resin composed of three
components, x, y and z are used in the range of x=10 to 90, y=5 to
85 and z=5 to 85, and preferably x=40 to 80, y=10 to 50 and z=10 to
50.
[0236] The molecular weight of the resin of (BN), preferably the
resin having the repeating structural unit represented by formula
(a), is preferably from 1,000 to 200,000, and more preferably from
3,000 to 50,000 in terms of a weight average molecular weight. The
molecular weight distribution of the resin is in the range of from
1 to 10, preferably from 1 to 3, and more preferably from 1 to 1.5.
As the molecular weight distribution is smaller, the resolution is
higher, the resist profile is better, the sidewalls of the resist
patterns are smoother, and the resist patterns are more excellent
in the edge roughness.
[0237] The content of the repeating unit represented by formula (a)
is from 5 to 100% by mole, and preferably from 10 to 90% by mole,
based on the alkali-soluble resin.
[0238] The alkali-soluble resin containing the structural unit
represented by formula (a) for use in the present invention can be
synthesized by methods described in Macromolecules, 28(11),
3787-3789 (1995), Polym. Bull. (Berlin), 24(4), 385-389 (1990) and
JP-A-8-286375. Specifically, the desired alkali-soluble resin can
be obtained by a radical polymerization method or a living anion
polymerization method.
[0239] The resins may be used individually or as a mixture of two
or more thereof.
[0240] The weight average molecular weight is expressed using a
value determined by gel permeation chromatography and calculated in
terms of polystyrene.
[0241] An alkali-dissolution rate of the alkali-soluble resin is
preferably not less than 20 angstrom/second, and more preferably
not less than 200 angstrom/second, when measured in a 0.261N
aqueous solution of tetramethylammonium hydroxide (TMAH) at
23.degree. C.
[0242] In the present invention, the alkali-soluble resin having a
repeating unit represented by formula (a) may be used individually
or together with other alkali-soluble resins. With respect to a
ratio of the resins, the amount of other alkali-soluble resins used
is at most 100 parts by weight based on 100 parts by weight of the
alkali-soluble resin having a repeating unit represented by formula
(a). Examples of other alkali-soluble resins used in combination
include novolac resins, hydrogenated novolac resins,
acetone-pyrogallol resins, styrene-maleic anhydride copolymers,
carboxy group-containing methacrylic resins and derivatives
thereof, but the present invention should not be construed as being
limited thereto.
[0243] The amount of the resin (BN) used is in the range of from 30
to 95% by weight, preferably from 40 to 90% by weight, and more
preferably from 50 to 80% by weight, based on the total solid
content of the resist composition.
[0244] <<Crosslinking Agent Crosslinking by the Action of an
Acid (Hereinafter, also Referred to as "Component (C)" or
"Crosslinking Agent of (C)")>>
[0245] The crosslinking agent crosslinking by the action of an acid
for use in the negative resist composition of the present invention
(hereinafter, also referred to as "acid crosslinking agent" or
simply as "crosslinking agent") is a compound capable of
crosslinking the alkali-soluble resin in the presence of an acid,
for example, an acid generated upon irradiation of radiation. The
crosslinking agent of (C) includes, for example, a compound
containing at least one substituent (hereinafter, referred to as
"crosslinkable substituent") having a crosslinking reactivity with
the alkali-soluble resin.
[0246] Specific examples of the crosslinkable substituent
include:
[0247] (i) a hydroxyalkyl group or a derivative thereof, e.g., a
hydroxyalkyl group, an alkoxyalkyl group or an acetoxyalkyl
group;
[0248] (ii) a carbonyl group or a derivative thereof, e.g., a
formyl group or a carboxyalkyl group;
[0249] (iii) a substituent having a nitrogen-containing group,
e.g., a dimethylaminomethyl group, a diethylaminomethyl group, a
dimethylolaminomethyl group, a diethylolaminomethyl group or a
morpholinomethyl group;
[0250] (iv) a substituent having a glycidyl group, e.g., a glycidyl
ether group, a glycidyl ester group or a glycidyl amino group;
[0251] (v) an aromatic derivative, for example, an aralkyloxyalkyl
group or an arylcarbonyloxyalkyl group, e.g., a benzyloxymethyl
group or a benzoyloxymethyl group; and
[0252] (vi) a substituent having a polymerizable multi-bond, e.g.,
a vinyl group or an isopropenyl group.
[0253] As the crosslinkable substituent in the crosslinking agent
of (C) according to the present invention, for example, a
hydroxyalkyl group and an alkoxyalkyl group are preferred, and an
alkoxymethyl group is more preferred.
[0254] The crosslinking agent containing the crosslinkable
substituent includes, for example,
[0255] (i) a methylol group-containing compound, e.g., a methylol
group-containing melamine compound, a methylol group-containing
benzoguanamine compound, a methylol group-containing urea compound,
a methylol group-containing glycoluril compound or a methylol
group-containing phenol compound;
[0256] (ii) an alkoxyalkyl group-containing compound, e.g., an
alkoxyalkyl group-containing melamine compound, an alkoxyalkyl
group-containing benzoguanamine compound, an alkoxyalkyl
group-containing urea compound, an alkoxyalkyl group-containing
glycoluril compound or an alkoxyalkyl group-containing phenol
compound;
[0257] (iii) a carboxymethyl group-containing compound, e.g., a
carboxymethyl group-containing melamine compound, a carboxymethyl
group-containing benzoguanamine compound, a carboxymethyl
group-containing urea compound, a carboxymethyl group-containing
glycoluril compound or a carboxymethyl group-containing phenol
compound; and
[0258] (iv) an epoxy compound, e.g., a Bisphenol A based epoxy
compound, a Bisphenol F based epoxy compound, a Bisphenol S based
epoxy compound, a novolac resin based epoxy compound, a resol resin
based epoxy compound or a poly(hydroxystyrene) based epoxy
compound.
[0259] A resin wherein the crosslinkable substituent described
above is introduced into an acidic functional group of the
alkali-soluble resin so as to have a property of crosslinking agent
can also be used as the crosslinking agent. In such a case, the
introduction ratio of crosslinkable substituent is controlled
ordinarily in a range of from 5 to 60% by mole, more preferably
from 10 to 50% by more, and still more preferably from 15 to 40% by
mole, based on the total acidic functional group in the
alkali-soluble resin. When the introduction ratio of crosslinkable
substituent is less than 5% by weight, it is difficult to cause the
sufficient crosslinking reaction, and as a result, problems, for
example, film thickness loss and swelling phenomenon and meandering
of pattern are apt to occur. On the other hand, the ratio exceeding
60% by weight results in decrease in alkali solubility of the
alkali-soluble resin, thereby tending to degradation of developing
property.
[0260] As the crosslinking agent of (C) for use in the negative
resist composition of the present invention, an alkoxymethylated
urea compound or a polymer thereof and an alkoxymethylated
glycoluril compound or a polymer thereof are preferred.
[0261] Particularly preferred examples of the crosslinking agent
(C1) include a compound represented by any one of formulae (2) to
(4) described hereinbefore and an alkoxymethylated melamine
compound.
[0262] R.sub.5b in formulae (2) to (4) each independently
represents a hydrogen atom, an alkyl group (preferably having from
1 to 5 carbon atoms, more preferably having from 1 to 3 carbon
atoms, for example, methyl, ethyl or propyl group) or an acyl group
(preferably having from 2 to 6 carbon atoms, more preferably having
from 2 to 4 carbon atoms, for example, acetyl or propionyl
group).
[0263] R.sub.6b to R.sub.9b in formula (2) each independently
represent a hydrogen atom, a hydroxy group, an alkyl group
(preferably having from 1 to 5 carbon atoms, more preferably having
from 1 to 3 carbon atoms, for example, methyl, ethyl or propyl
group) or an alkoxy group (preferably having from 1 to 5 carbon
atoms, more preferably having from 1 to 3 carbon atoms, for
example, methoxy, ethoxy or propoxy group).
[0264] X in formula (2) represents a single bond, a methylene group
or an oxygen atom. X is preferably a single bond or a methylene
group.
[0265] The above groups may further have a substituent, for
example, an alkyl group, e.g., methyl or ethyl group, an alkoxy
group, e.g., methoxy or ethoxy group, a hydroxy group or a halogen
atom.
[0266] Specific examples of the compounds represented by formulae
(2) to (4) and alkoxymethylated melamine compounds are set forth
below, but the present invention should not be construed as being
limited thereto. 9596979899
[0267] The crosslinking agent can be obtained by conducting a
condensation reaction of a urea compound or glycoluril compound
with formalin to introduce a methylol group, etherifying the
methylol group with a lower alcohol, e.g., methyl alcohol, ethyl
alcohol, propyl alcohol or butyl alcohol, and cooling the reaction
solution, followed by recovering the deposited compound or resin.
The crosslinking agent is also available as a commercial product,
for example, Cymel (manufactured by Mitsui Cyanamid Co., Ltd.) or
Nikarad (manufactured by Sanwa Chemical Co., Ltd.).
[0268] Particularly preferred examples of the crosslinking agent
(C2) include a compound selected from phenol derivatives having
from 1 to 6 benzene rings and two or more hydroxymethyl groups
and/or alkoxymethyl groups connected to any of the benzene rings
per molecule.
[0269] A phenol derivative having a molecular weight of not more
than 1,500, containing from 1 to 6 benzene rings, and having at
least two groups selected from hydroxymethyl group and an
alkoxymethyl group, connected concentrically to one of the benzene
rings or connected dispersedly to the benzene rings in the molecule
thereof is preferably used.
[0270] The alkoxymethyl group connected to the benzene ring
preferably includes an alkoxymethyl group having not more than 6
carbon atoms. Specific examples thereof include methoxymethyl,
ethoxymethyl, n-propoxymethyl, isopropoxymethyl, n-butoxymethyl,
isobutoxymethyl, sec-butoxymethyl and tert-butoxymethyl groups. An
alkoxy- substituted alkoxy group, e.g., 2-methoxyethoxy or
2-methoxy-1-propoxy group is also preferred.
[0271] Among the phenol derivatives, those particularly preferred
are set forth below. 100101102
[0272] wherein, L.sup.1 to L.sup.8 which may be the same or
different, each represent a hydroxymethyl group, a methoxymethyl
group or an ethoxymethyl group.
[0273] The phenol derivative having a hydroxymethyl group can be
obtained by reacting a corresponding phenol compound free from a
hydroxymethyl group (the compound represented by the
above-described formula wherein all of L.sup.1 to L.sup.8 represent
hydrogen atoms) with formaldehyde in the presence of a base
catalyst. At that time, it is preferred to carry out the reaction
at a temperature of not higher than 60.degree. C. in order to
prevent the occurrence of resinification or gelation. Specifically,
the phenol derivative can be synthesized according to methods
described, e.g., in JP-A-6-282067 and JP-A-7-64285.
[0274] The phenol derivative having an alkoxymethyl group can be
obtained by reacting a corresponding phenol derivative having a
hydroxymethyl group with an alcohol in the presence of an acid
catalyst. At that time, it is preferred to carry out the reaction
at a temperature of not higher than 100.degree. C. in order to
prevent the occurrence of resinification or gelation. Specifically,
the phenol derivative can be synthesized according to methods
described, e.g., in European Patent 632,003.
[0275] The phenol derivatives having a hydroxymethyl group or an
alkoxymethyl group are preferable in view of the storage stability,
and the phenol derivatives having an alkoxymethyl group are
particularly preferable from the standpoint of storage stability.
The phenol derivatives having at least two groups of a
hydroxymethyl group and alkoxymethyl group in total, wherein these
groups are connected concentrically to one of the benzene rings or
dispersedly to the benzene rings, may be used individually or as a
combination of two or more thereof.
[0276] The crosslinking agent is ordinarily used in an amount of
from 3 to 70% by weight, and preferably from 5 to 50% by weight,
base on the total solid content of the negative resist composition.
When the amount of the crosslinking agent added is less than 3% by
weight, the film remaining ratio decreases, and on the other hand,
when the amount exceeds 70% by weight, the resolution decreases and
a further disadvantage in stability of the resist solution during
storage may occur.
[0277] The compounds having an N-hydroxymethyl group, an
N-alkoxymethyl group or an N-acyloxymethyl group and the phenol
derivatives having a hydroxymethyl group or an alkoxymethyl group
may be used as a combination of two or more thereof.
[0278] <<Other Components for Use in the Resist Composition
of the Present Invention>>
[0279] The resist composition of the present invention may further
contain other components, for example, an organic basic compound, a
dye and a surface active agent, if desired.
[0280] <Organic Basic Compound>
[0281] A preferred organic basic compound which can be used in the
present invention is a compound having a basicity stronger than
that of phenol. Among the compounds, a nitrogen-containing basic
compound is preferably used.
[0282] Preferred chemical environments for the nitrogen-containing
basic compound include a structure represented by the following
formula (A), (B), (C), (D) or (E): 103
[0283] wherein R.sup.250, R.sup.251 and R.sup.252, which may be the
same or different, each represent a hydrogen atom, an alkyl group
having from 1 to 6 carbon atoms, an aminoalkyl group having from 1
to 6 carbon atoms, a hydroxyalkyl group having from 1 to 6 carbon
atoms or a substituted or unsubstituted aryl group having from 6 to
20 carbon atoms, or R.sup.251 and R.sup.252 may be combined with
each other to form a ring.
[0284] R.sup.253, R.sup.254, R.sup.255 and R.sup.256, which may be
the same or different, each represent an alkyl group having from 1
to 6 carbon atoms.
[0285] A more preferable compound is a nitrogen-containing basic
compound having at least two nitrogen atoms of different chemical
environments per molecule. A compound containing both a substituted
or unsubstituted amino group and a ring structure containing a
nitrogen atom, and a compound containing an alkylamino group are
particularly preferred.
[0286] Preferred specific examples of the nitrogen-containing basic
compound include a substituted or unsubstituted guanidine, a
substituted or unsubstituted aminopyridine, a substituted or
unsubstituted aminoalkylpyridine, a substituted or unsubstituted
aminopyrrolidine, a substituted or unsubstituted indazole, a
substituted or unsubstituted imidazole, a substituted or
unsubstituted pyrazole, a substituted or unsubstituted pyrazine, a
substituted or unsubstituted pyrimidine, a substituted or
unsubstituted purine, a substituted or unsubstituted imidazoline, a
substituted or unsubstituted pyrazoline, a substituted or
unsubstituted piperazine, a substituted or unsubstituted
aminomorpholine and a substituted or unsubstituted
aminoalkylmorpholine. Preferred examples of the substituent include
an amino group, an aminoalkyl group, an alkylamino group, an
aminoaryl group, an arylamino group, an alkyl group, an alkoxy
group, an acyl group, an acyloxy group, an aryl group, an aryloxy
group, a nitro group, a hydroxy group and a cyano group.
[0287] Particularly preferable compounds include guanidine,
1,1-dimethylguanidine, 1,1,3,3-tetramethylguanidine, imidazole,
2-methylimidazole, 4-methylimidazole, N-methylimidazole,
2-phenylimidazole, 4,5-diphenylimidazole, 2,4,5-triphenylimidazole,
2-aminopyridine, 3-aminopyridine, 4-aminopyridine,
2-dimethylaminopyridine, 4-dimethylaminopyridine,
2-diethylaminopyridine, 2-(aminomethyl)pyridine,
2-amino-3-methylpyridine, 2-amino-4-methylpyridine,
2-amino-5-methylpyridine, 2-amino-6-methylpyridine,
3-aminoethylpyridine, 4-aminoethylpyridine, 3-aminopyrrolidine,
piperazine, N-(2-aminoethyl)piperazine, N-(2-aminoethyl)piperidine,
4-amino-2,2,6,6-tetramethylpiperidine, 4-piperidinopiperidine,
2-iminopiperidine, 1-(2-aminoethyl)pyrrolidine, pyrazole,
3-amino-5-methylpyrazole, 5-amino-3-methyl-1-p-tolylpyrazole,
pyrazine, 2-(aminomethyl)-5-methylpyrazine, pyrimidine, 2,
4-diaminopyrimidine, 4,6-dihydroxypyrimidine, 2-pyrazoline,
3-pyrazoline, N-aminomorpholine and N-(2-aminoethyl)morpholine.
However, the present invention should not be construed as being
limit to these compounds.
[0288] The organic basic compounds may be used individually or as a
combination of two or more thereof.
[0289] With respect to a ratio of the acid generator and the
organic basic compound used in the positive resist composition, a
molar ratio of (acid generator)/(organic basic compound) is
preferably from 2.5 to 300. When the molar ratio is less than 2.5,
the sensitivity is low and the resolution decreases in some cases.
On the other hand, when the molar ratio exceeds 300, the resist
pattern sizes are changed with the lapse of time from exposure to
heat treatment, and the resolution also decreases in some cases.
The molar ratio of (acid generator)/(organic basic compound) is
preferably from 5.0 to 200, and more preferably from 7.0 to
150.
[0290] The amount of organic basic compound used in the negative
resist composition is ordinarily from 0.001 to 10% by weight, and
preferably from 0.01 to 5% by weight, based on the total solid
content of the resist composition. When the amount of organic basic
compound is less than 0.001% by weight, the effect of adding the
basic organic compound may not be obtained. On the other hand, when
the amount exceeds 10% by weight, decrease of the sensitivity and
deterioration of the developing property in the unexposed area may
tend to occur.
[0291] <Dye>
[0292] Suitable dyes include oil dyes and basic dyes. Specific
examples thereof include Oil Yellow #101, Oil Yellow #103, Oil Pink
#312, Oil Green BG, Oil Blue BOS, Oil Blue #603, Oil Black BY, Oil
Black BS, Oil Black T-505 (these dyes are manufactured by Orient
Chemical Industries, Ltd.), Crystal Violet (CI 42555), Methyl
Violet (CI 42535), Rhodamine B (CI 45170B), Malachite Green (CI
42000) and Methylene Blue (CI 52015).
[0293] <Solvent>
[0294] The resist composition of the present invention is dissolved
in a solvent capable of dissolving the components described above
and applied to a support. Preferred examples of the solvent used
include ethylene dichloride, cyclohexanone, cyclopentanone,
2-heptanone, .gamma.-butyrolactone, methyl ethyl ketone, ethylene
glycol monomethyl ether, ethylene glycol monoethyl ether,
2-methoxyethyl acetate, ethylene glycol monoethyl ether acetate,
propylene glycol monomethyl ether, propylene glycol monomethyl
ether acetate, toluene, ethyl acetate, methyl lactate, ethyl
lactate, methyl methoxypropionate, ethyl ethoxypropionate, methyl
pyruvate, ethyl pyruvate, propyl pyruvate, N,N-dimethylformamide,
dimethyl sulfoxide, N-methylpyrrolidone and tetrahydrofuran. The
solvents are used individually or as a mixture of two or more
thereof.
[0295] A particularly preferred solvent includes propylene glycol
monomethyl ether acetate and a mixed solvent of propylene glycol
monomethyl ether acetate/propylene glycol monomethyl ether.
[0296] <Surface Active Agent>
[0297] Into the resist composition of the present invention, a
fluorine-based and/or silicon-based surface active agent can be
preferably incorporated.
[0298] It is preferred that the resist composition of the present
invention contains one or more of a fluorine-based surface active
agent, a silicon-based surface active agent and a surface active
agent containing both a fluorine atom and a silicon atom.
[0299] The incorporation of surface active agent together with the
components described above into the resist composition of the
present invention is particularly effective for the formation of
finer line width pattern and further improves the development
defect.
[0300] Examples of the surface active agent include those described
in JP-A-62-36663, JP-A-61-226746, JP-A-61-226745, JP-A-62-170950,
JP-A-63-34540, JP-A-7-230165, JP-A-8-62834, JP-A-9-54432 and
JP-A-9-5988. Commercially available surface active agents described
below may also be used as they are.
[0301] Examples of the commercially available surface active agent
used include fluorine-based or silicon-based surface active agents,
e.g., Eftop EF301 and EF303 (manufactured by Shin-Akita Kasei Co.,
Ltd.), Florad FC430 and FC431 (manufactured by Sumitomo 3M Ltd.),
Megafac F171, F173, F176, F189 and R.sub.08 (manufactured by
Dainippon Ink & Chemicals, Inc.), Surflon S-382, SC101, 102,
103, 104, 105 and 106 (manufactured by Asahi Glass Co., Ltd.) and
Troysol S-366 (manufactured by Troy Chemical Corp.). A polysiloxane
polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) is
also used as a silicon-based surface active agent.
[0302] The amount of surface active agent used is ordinarily from
0.001 to 2% by weight, and preferably from 0.01 to 1% by weight,
based on the total solid content of the resist composition.
[0303] The surface active agents may be used individually or as a
combination of two or more thereof.
[0304] Specific examples of the surface active agent other than
those described above include a nonionic surface active agent, for
example, a polyoxyethylene alkyl ether, e.g., polyoxyethylene
lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl
ether or polyoxyethylene oleyl ether, a polyoxyethylene alkyl aryl
ether, e.g., polyoxyethylene octyl phenol ether or polyoxyethylene
nonyl phenol ether, a polyoxyethylene/polyoxypropylene block
copolymer, a sorbitan fatty acid ester, e.g., sorbitan monolaurate,
sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate,
sorbitan trioleate or sorbitan tristearate, and a polyoxyethylene
sorbitan fatty acid ester, e.g., polyoxyethylene sorbitan
monolaurate, polyoxyethylene sorbitan monopalmitate,
polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan
trioleate or polyoxyethylene sorbitan tristearate.
[0305] The amount of such other surface active agent is ordinarily
from not more than 2 parts by weight, and preferably not more than
1 part by weight, based on 100 parts by weight of the total solid
content of the resist composition according to the present
invention.
[0306] The pattern formation process on a resist film in the
production of precise integrated circuit device comprises applying
the resist composition of the present invention to a substrate (for
example, a silicon/silicon dioxide film or a transparent substrate,
e.g., a glass substrate or an ITO substrate) according to an
appropriate method, for example, using a spinner or coater and
exposing the coated layer through a predefined mask, followed by
heating, developing, rinsing and drying, whereby a good resist
pattern is formed.
[0307] The exposure light used includes an electron beam, EUV
(extreme ultraviolet) and an X-ray.
[0308] In the present invention, a known inorganic or organic
anti-reflective coating may be used, if desired. Further, the
anti-reflective coating may be coated on the resist layer.
[0309] Suitable examples of the anti-reflective coating used for an
under layer of the resist layer include an inorganic coating type,
for example, titanium, titanium dioxide, titanium nitride, chromium
oxide, carbon or amorphous silicon, and an organic coating type
comprising a light absorbent and a polymer material. The former
requires an apparatus, for example, a vacuum deposition apparatus,
a CVD apparatus or a sputtering apparatus, for the formation of
anti-reflective coating. The organic anti-reflective coating
includes, for example, a coating comprising a condensate of a
diphenylamine derivative with a formaldehyde-modified melamine
resin, an alkali-soluble resin and a light absorbent as described
in JP-B-7-69611, a coating comprising a reaction product of a
maleic anhydride copolymer with a diamine light absorbent as
described in U.S. Pat. No. 5,294,680, a coating comprising a resin
binder and a methylolmelamine thermal crosslinking agent as
described in JP-A-6-118631, a coating comprising an acrylic resin
containing a carboxylic acid group, an epoxy group and a light
absorbing group in the same molecule as described in JP-A-6-118656,
a coating comprising methylolmelamine and a benzophenone light
absorbent as described in JP-A-8-87115, and a coating comprising a
low molecular weight light absorbent added to a polyvinyl alcohol
resin as described in JP-A-8-179509.
[0310] Also, a commercially available organic anti- reflective
coating, for example, DUV-30 Series and DUV-40 Series (manufactured
by Brewer Science, Inc.) and AR-2, AR-3 and AR-5 (manufactured by
Shipley Co., Ltd.) are employed as the organic anti-reflective
coating.
[0311] A developing solution for the resist composition of the
present invention is ordinarily an aqueous solution of an alkali,
for example, an inorganic alkali, e.g., sodium hydroxide, potassium
hydroxide, sodium carbonate, sodium silicate, sodium metasilicate
or aqueous ammonia; a primary amine, e.g., ethylamine or
n-propylamine; a secondary amine, e.g., diethylamine or
di-n-butylamine; a tertiary amine, e.g., triethylamine or
methyldiethylamine; an alcoholamine, e.g., dimethylethanolamine or
triethanolamine; a quaternary ammonium salt, e.g.,
tetramethylammonium hydroxide, tetraethylammonium hydroxide or
choline; and a cyclic amine, e.g., pyrrole or piperidine. Further,
the aqueous solution of alkali containing an appropriate amount of
an alcohol, e.g., isopropyl alcohol or a surface active agent,
e.g., a nonionic surface active agent may be used.
[0312] Of the developing solutions, a developing solution
containing a quaternary ammonium salt is preferred, and a
developing solution containing tetramethylammonium hydroxide or
choline is more preferred.
[0313] The present invention will be described in more detail with
reference to the following examples, but the present invention
should not be construed as being limited thereto.
EXPERIMENTAL EXAMPLE
[0314] Measurement of Reduction Potential
[0315] The reduction potential of acid generator was measured by a
cyclic voltammetry method. Specifically, each of the acid
generators shown in Table 1 below was dissolved in distilled
acetonitrile under argon atmosphere to prepare a 1 mM solution of
the acid generator for the measurement. A 0.1 mM solution of
tetrabutylammonium perchlorate was used as a supporting
electrolyte. With respect to electrodes, MP-2 (manufactured by
Yanaco LID Co., Ltd.), C-2U (manufactured by Yanaco LID Co., Ltd.)
and Ag/AgCl were used as a working electrode, a counter electrode
and a reference electrode, respectively. The measurement was
conducted at 23.5.degree. C. The scanning speed was 50 mV/cm.sup.2.
Since the acid generator was decomposed by reduction and the
reaction was irreversible, only a reduction peak was observed.
1TABLE 1 Reduction Potential Chemical Structure (vs SCE) 104 -1.14
V 105 -0.78 V 106 -0.61 V 107 -0.74 V 108 -0.68 V 109 -0.77 V 110
-0.64 V
[0316] (1) Synthesis of Compound of (A1)
[0317] In 200 ml of benzene was dissolved 10 g of dibenzothiophene,
and the resulting solution was cooled at 5.degree. C. and 40 ml of
concentrated sulfuric acid was gradually added dropwise thereto
with stirring. The temperature of solution was raised to room
temperature, followed by stirring for 48 hours. The reaction
mixture was poured onto ice, and the aqueous layer was extracted
three times with each one liter of ether. The aqueous layer was
cooled at 0.degree. C. and an aqueous solution containing 16.95 g
of trimethylammonium 3,5-ditrifluoromethylben- zenesulfonate in one
liter of water was added dropwise thereto, followed by stirring at
0.degree. C. for 2 hours. The reaction mixture was extracted three
times with each one liter of chloroform. The organic layer was
washed with water and concentrated to obtain 2.5 g of the oil of
Compound A1-1.
[0318] Compounds A1-2 to A1-15 can be synthesized in a similar
manner.
[0319] (2) Synthesis of Compound of (A2)
[0320] (2-1) Synthesis of tetramethylammonium
pentafluorobenzenesulfonate
[0321] In 100 ml of methanol was dissolved 25 g of
pentafluorobenzenesulfo- nyl chloride under cooling with ice, and
100 g of a 25% aqueous solution of tetramethylammonium hydroxide
was gradually added thereto. The mixture was stirred for 3 hours at
room temperature to obtain a solution of tetramethylammonium
pentafluorobenzenesulfonate. The solution was used for salt
exchange with a sulfonium salt or an iodonium salt.
[0322] (2-2) Synthesis of triphenylsulfonium
pentafluorobenzenesulfonate
[0323] In 800 ml of benzene was dissolved 50 g of diphenyl
sulfoxide, and after the addition of 200 g of aluminum chloride,
the mixture was refluxed for 24 hours. The reaction solution was
gradually poured into 2 liters of ice water, and after the addition
of 400 ml of concentrated hydrochloric acid, the mixture was heated
at 70.degree. C. for 10 minutes. The aqueous solution was washed
with 500 ml of ethyl acetate, and after filtration, a solution
containing 200 g of ammonium iodide dissolved in 400 ml of water
was added thereto. The powder thus precipitated was collected by
filtration, washed with water and then with ethyl acetate, and
dried to obtain 70 g of triphenylsulfonium iodide.
[0324] In 1,000 ml of methanol was dissolved 30.5 g of
triphenylsulfonium iodide, and after the addition of 19.1 g of
silver oxide to the solution, the mixture was stirred at room
temperature for 4 hours. The reaction solution was filtered and to
the filtrate was added an excessive amount of the solution of
tetramethylammonium pentafluorobenzenesulfonate described above.
The reaction solution was concentrated, the resulting residue was
dissolved in 500 ml of dichloromethane, and the solution was washed
with a 5% aqueous solution of tetramethylammonium hydroxide and
then with water. The organic layer was dried over anhydrous sodium
sulfate, and then concentrated to obtain triphenylsulfonium
pentafluorobenzenesulfonate of Compound (I-1).
[0325] (2-3) Synthesis of di(4-tert-amylphenyl)iodonium
pentafluorobenzenesulfonate
[0326] To a mixture of 60 g of tert-amylbenzene, 39.5 g of
potassium iodate, 81 g of acetic anhydride and 170 ml of
dichloromethane was gradually added dropwise 66.8 g of concentrated
sulfuric acid under cooling with ice. After stirring under cooling
with ice for 2 hours, the mixture was further stirred at room
temperature for 10 hours. To the reaction solution was added 500 ml
of water under cooling with ice, and the resulting mixture was
extracted with dichloromethane. The organic layer was washed with
an aqueous solution of sodium hydrogen carbonate and then with
water, and concentrated to obtain di(4-tert-amylphenyl)iodo- nium
sulfate. The resulting sulfate was added to an excessive amount of
the solution of tetramethylammonium pentafluorobenzenesulfonate
described above. To the solution was added 500 ml of water, and the
solution was extracted with dichloromethane. The organic layer was
washed with a 5% aqueous solution of tetramethylammonium hydroxide
and then with water, and concentrated to obtain
di(4-tert-amylphenyl)iodonium pentafluorobenzenesulfonate of
Compound (III-1).
[0327] (3) Synthesis of Acid-Decomposable Resin of (BP)
[0328] (3-1) Synthesis of Resin (B-21)
[0329] In 120 ml of butyl acetate were dissolved 32.4 g (0.2 mol)
of p-acetoxystyrene and 7.01 g (0.07 mol) of tert-butyl
methacrylate. To the solution were added three times each 0.033 g
of azobisisobutyronitrile (AIBN) at an interval of 2.5 hours at
80.degree. C. with stirring in a nitrogen gas stream and then the
mixture was further stirred for 5 hours, whereby the polymerization
reaction was conducted. The resulting reaction solution was poured
into 1,200 ml of hexane to precipitate a white resin. The resin
obtained was dried and then dissolved in 200 ml of methanol.
[0330] To the solution was added an aqueous solution prepared by
dissolving 7.7 g (0.19 mol) of sodium hydroxide in 50 ml of water,
and the mixture was refluxed by heating for one hour to hydrolyze
the resin. Then, the reaction mixture was diluted by adding 200 ml
of water and neutralized with hydrochloric acid to deposit a white
resin. The resin was collected by filtration, washed with water,
dried and then dissolved in 200 ml of tetrahydrofuran to prepare a
solution. The solution was added dropwise to 5 liters of ultrapure
water with vigorous stirring to reprecipitate. The reprecipitation
operation was repeated three times. The resin thus obtained was
dried in a vacuum dryer at 120.degree. C. for 12 hours to obtain
copoly(p-hydroxystyrene/tert-butyl methacrylate).
[0331] (3-2) Synthesis of Resin (B-3)
[0332] In 50 ml of pyridine was dissolved 10 g of
poly(p-hydroxystyrene) (VP-8000 manufactured by Nippon Soda Co.,
Ltd.). To the solution was dropwise added 3.63 g of di-tert-butyl
dicarbonate with stirring at room temperature. After stirring for 3
hours at room temperature, the reaction mixture was dropwise added
to a solution containing 20 g of concentrated hydrochloric acid in
one liter of ion-exchanged water. The powder thus deposited was
collected by filtration, washed with water and dried to obtain
Resin (B-3).
[0333] (3-3) Synthesis of Resin (B-32)
[0334] In 300 ml of toluene was dissolved 83.1 g (0.5 mol) of
p-cyclohexylphenol, and to the solution were added 150 g of
2-chloroethyl vinyl ether, 25 g of sodium hydroxide, 5 g of
tetrabutylammonium bromide and 60 g of triethylamine, followed by
reacting at 120.degree. C. for 5 hours. The reaction solution was
washed with water, and the excess 2-chloroethyl vinyl ether and
toluene were distilled off. The oil thus obtained was purified by
distillation under a reduced pressure to obtain
4-cyclohexylphenoxyethyl vinyl ether.
[0335] In 80 ml of tetrahydrofuran were dissolved 20 g of
poly(p-hydroxystyrene) (VP-8000 manufactured by Nippon Soda Co.,
Ltd.) and 6.5 g of 4-cyclohexylphenoxyethyl vinyl ether. To the
solution was added 0.01 g of p-toluenesulfonic acid, followed by
reacting at room temperature for 18 hours. The reaction solution
was added dropwise to 5 liters of distilled water with vigorous
stirring, and the powder thus deposited was collected by filtration
and dried to obtain Polymer (B-32).
[0336] Other resins of component (BP) were synthesized in a similar
manner. With the polymers for use in the examples described below,
the weight average molecular weight and the molar ratio of
repeating unit are shown below.
2 Weight Average Molar Ratio of Resin Molecular Weight Repeating
unit.sup.*) (B-3) 8,500 25/75 (B-4) 8,500 25/75 (B-21) 12,000 65/35
(B-26) 11,500 15/60/25 (B-28) 15,000 78/22 (B-30) 8,000 80/20
(B-31) 15,000 65/10/25 (B-32) 12,000 82/18 .sup.*)The molar ratio
of repeating unit is indicated using the repeating units of the
resins described in the specific examples of the resin of Component
(BP) hereinbefore and # the numerals in each polymer mean the molar
ratio of the repeating unit in order from left to right.
[0337] (4) Synthesis of Alkali-Soluble Resin of (BN)
[0338] (4-1) Synthesis of Resin a-(29)
[0339] In 30 ml of 1-methoxy-2-propanol were dissolved 3.9 g (0.024
mol) of 4-acetoxystyrene and 0.8 g (0.006 mol) of 4-methoxystyrene,
and while stirring the solution under a nitrogen gas stream, 70 ml
of a 1-methoxy-2-propanol solution containing 50 mg of a
polymerization initiator, i.e.,
2,2'-azobis(2,4-dimethylvaleronitrile) (V-65 manufactured by Wako
Pure Chemical Industries, Ltd.), 9.1 g (0.056 mol) of
4-acetoxystyrene and 1.9 g (0.014 mol) of 4-methoxystyrene was
added dropwise thereto at 70.degree. C. over a period of 2 hours.
After 2 hours, 50 mg of the initiator was additionally added
thereto and the reaction was further continued for 2 hours.
Thereafter, the temperature was raised to 90.degree. C. and the
reaction solution was stirred for one hour. The reaction solution
was allowed to cool and poured into one liter of ion-exchanged
water with vigorous stirring to deposit a white resin. The
resulting resin was dried and then dissolved in 100 ml of methanol.
To the solution was added a 25% aqueous solution of
tetramethylammonium hydroxide to hydrolyze the acetoxy group in the
resin. Then, the solution was neutralized with an aqueous solution
of hydrochloric acid to deposit a white resin. The resin was washed
with ion-exchanged water and dried under a reduced pressure to
obtain 11.6 g of Resin a-(29) according to the present
invention.
[0340] A weight average molecular weight (Mw) of the resin measured
by GPC and calculated in terms of polystyrene was 9,200 and degree
of dispersion (Mw/Mn) was 2.2. As a result of determining a
component ratio of the resin, it was found that a molar ratio of
x/y was 80/20.
[0341] (4-2) Synthesis of Resin a-(39)
[0342] In 100 ml of acetone was dissolved 12.0 g of
poly(4-hydroxystyrene) (Mw: 10,500; Mw/Mn: 1.2), and to the
solution were added 2.0 g of pyridine and then 1.3 g of acetic
anhydride, followed by reacting at 50.degree. C. with stirring for
3 hours. The reaction solution was poured into one liter of
ion-exchanged water with vigorous stirring to deposit a white
resin. The resulting resin was dried under a reduced pressure to
obtain 12.2 g of Resin a-(39) according to the present
invention.
[0343] A weight average molecular weight (Mw) of the resin measured
by GPC and calculated in terms of polystyrene was 11,400 and degree
of dispersion (Mw/Mn) was 1.2. As a result of determining a
component ratio of the resin, it was found that a molar ratio of
x/y (4-hydroxystyrene/4-acetoxystyrene) was 88/12.
[0344] (4-3) Synthesis of Resin a-(91)
[0345] In 30 ml of 1-methoxy-2-propanol were dissolved 3.8 g (0.015
mol) of 2-[(4'-hydoxyphenyl)carbonyloxy]ethyl methacrylate, 1.0 g
(0.009 mol) of 2-hydroxyethyl acrylate and 0.3 g (0.006 mol) of
acrylonitrile, and while stirring the solution under a nitrogen gas
stream, 70 ml of a 1-methoxy-2-propanol solution containing 50 mg
of a polymerization initiator, i.e.,
2,2'-azobis(2,4-dimethylvaleronitrile) (V-65 manufactured by Wako
Pure Chemical Industries, Ltd.), 8.8 g (0.035 mol) of
2-[(4'-hydoxyphenyl)carbonyloxy]ethyl methacrylate, 2.4 g (0.021
mol) of 2-hydroxyethyl acrylate and 0.7 g (0.014 mol) of
acrylonitrile was added dropwise thereto at 70.degree. C. over a
period of 2 hours. After 2 hours, 50 mg of the initiator was
additionally added thereto and the reaction was further continued
for 2 hours. Thereafter, the temperature was raised to 90.degree.
C. and the reaction solution was stirred for one hour. The reaction
solution was allowed to cool and poured into one liter of
ion-exchanged water with vigorous stirring to deposit a white
resin. The resulting resin was dried under a reduced pressure to
obtain 15.8 g of Resin a-(91) according to the present
invention.
[0346] A weight average molecular weight (Mw) of the resin measured
by GPC and calculated in terms of polystyrene was 11,000 and degree
of dispersion (Mw/Mn) was 1.5. As a result of determining a
component ratio of the resin, it was found that a molar ratio of
x/y/z was 60/30/10.
[0347] Other resins of component (BN) according to the present
invention were synthesized in a similar manner.
[0348] (5) Synthesis of Crosslinking Agent
[0349] (5-1) Synthesis of Crosslinking Agent [HM-0]
[0350] In a flask were put one mol of p-aminophenol, one mol of
sodium acetate and one liter of acetone, and to the mixture was
added dropwise one mol of isobutyric chloride under cooling with
ice. After 5 hours, the reaction mixture was poured into ice water
to deposit crystals. The crystals were collected by filtration to
obtain HM-0-X in a yield of 80%.
[0351] In a flask were put 0.8 mol of HM-0-X, 0.8 mol of potassium
hydroxide, 500 ml of water and 4.8 mol of a 37% aqueous formalin
solution, and the mixture was heated at 50.degree. C. for 5 hours
and then neutralized with acetic acid. The mixture was concentrated
under a reduced pressure, and the resulting oily product was
dissolved in a mixture of ethyl acetate and methanol (1/1) and
separated by SiO.sub.2 column chromatography to obtain the desired
Crosslinking Agent [HM-0] (L.sub.1=L.sub.2=CH.sub.2OH) as colorless
crystals in the total yield of 50%. 111
[0352] (5-2) Synthesis of Crosslinking Agent [HM-1]
[0353] To a 10% aqueous solution of potassium hydroxide was added
20 g of
1-[.alpha.-methyl-.alpha.-(4-hydroxyphenyl)ethyl]-4-[.alpha.,.alpha.-bis(-
4-hydroxyphenyl)ethyl]benzene (Trisp-PA manufactured by Honshu
Chemical Industry Co., Ltd.) with stirring to dissolve. While
stirring the solution, 60 ml of a 37% aqueous formalin solution was
gradually added thereto at room temperature over a period of 1
hour. After further stirring at room temperature for 6 hours, the
solution was poured into a diluted aqueous sulfuric acid solution.
The precipitates thus formed were collected by filtration,
sufficiently washed with water, and recrystallized from 30 ml of
methanol to obtain 20 g of white powder of phenol derivative
(Crosslinking Agent [HM-1]) containing hydroxymethyl groups having
the structure shown below. The purity thereof was 92% (determined
by a liquid chromatography method). 112
[0354] (5-3) Synthesis of Crosslinking Agent [MM-1]
[0355] To one liter of methanol was added 20 g of the phenol
derivative (Crosslinking Agent [HM-1]) having hydroxymethyl groups
obtained above with heating and stirring to dissolve. To the
solution was added 1 ml of concentrated sulfuric acid, and the
mixture was refluxed by heating for 12 hours. After the completion
of the reaction, the reaction solution was cooled and 2 g of
potassium carbonate was added thereto. The mixture was sufficiently
concentrated, and 300 ml of ethyl acetate was added thereto. The
solution was washed with water and concentrated to dryness to
obtained 22 g of phenol derivative (Crosslinking Agent [MM-1])
containing methoxymethyl groups having the structure shown below as
a white solid. The purity thereof was 90% (determined by a liquid
chromatography method). 113
EXAMPLES 101 TO 118 AND COMPARATIVE EXAMPLES 101 TO 105
[0356] 10--Application of resist composition
[0357] Each of the components shown in Table 2 below in an amount
described below was dissolved in 26.0 g (in total) of the
solvent(s) to prepare a solution of resist composition. In Table 2,
when plural compounds are used in each component, a ratio thereof
is indicated by weight.
3 Acid-decomposable resin (BP) 2.0 g Acid generator 0.20 g Basic
compound (if desired) 0.0040 g Surface active agent (if desired)
0.0020 g
[0358] The solution of resist composition was subjected to
microfiltration using a membrane filter having a pore size of 0.1
.mu.m to prepare a resist solution.
[0359] The resist solution was coated on a 6-inch silicon wafer
using a spin coater (Mark 8 manufactured by Tokyo Electron Ltd.)
and baked at 110.degree. C. for 90 seconds to prepare a uniform
film having a thickness of 0.30 .mu.m.
4TABLE 2 Surface Resin Acid Basic Active Example (BP) Generator
Solvent Compound Agent 101(119) B-4 A1-3/I-1 = S1/S3/58 = (4) W1
4/6 80/15/5 102(120) B-32 A1-4/I-9 = S1/S6 = (4) W1 2/3 80/20
103(121) B-26 A1-15/I-18 = S1/S7 = (9) W1 2/1 75/25 104(122) B-21
A1-13/II-1 = S1/S6/S10 = (1) W5 21/1 65/20/15 105(123) B-30
A1-7/I-20 = S1/S9 = (2) Wi 1/1 90/10 106(124) B-31 A1-12/II-4 =
S1/S11 = (6) W2 3/1 80/20 107(125) B-3 A1-4/II-5C = S1/S3/S8 = (9)
W1 3/1 75/20/5 108(126) B-26 A1-13 S1 (3) W1 109(127) B-28 BCFY S1
(7) W3 110(128) B-30 A1-5 S3 (5) Wi 111(129) B-31 A1-6 S1 (9) W5
112(130) B-28 A1-7 S2 (8) W3 113(131) B-30 A1-8 S7 (9) W4 114(132)
B-31 A1-9 S4 (6) W1 115(133) B-26 A1-12 S8 (10) W1 116(134) B-4
A1-16/I-1 = S1 (4) W1 8/2 117(135) B-4 A1-17/I-1 = S1 (4) W1 8/2
118(136) B-4 A1-19/I-1 = S1 (4) W1 8/2 Com- Surface parative Resin
Acid Basic Active Example (BP) Generator Solvent Compound Agent
101(106) B-4 I-1 S3 (4) W1 102(107) B-32 I-9 S5 (4) W1 103(108)
B-26 I-18 S1 (9) W1 104(109) B-21 Il-1 S1 (1) W5 105(110) B-31 II-1
S5 (6) W1 The abbreviations of components used in Table 2 are
explained below. Acid generator: BCFY: 114 Basic Compounds: (1):
1,8-Diazabicyclo[4.3.0]non-5-ene (2): 2,6-Diisopropylaniiine (3):
4-Dimethylaminopyridine (4): 2,4,5-Triphenylimidazole (5):
Piperazine (6): 1,5-Diazabicyclo[4.3.0]non-5-ene (7):
1,5-Diazabicyclo[2.2.2]octane (8): Hexamethylenetetramine (9):
1-Cyclohexyl-3-(2-morpholinomethyl)-2-thiourea (CHMETU) (10):
Phenylguanidine Surface Active Agents: W-1: Megafac F176
(manufactured by Dainippon Ink & Chemicals, Inc.)
(fluorine-based) W-2: Megafac R08 (manufactured by Dainippon Ink
& Chemicals, Inc.) (fluorine- and silicon-based) W-3:
Polysiloxane polymer KP-341 (manufactured by Shin- Etsu Chemical
Industry Co., Ltd.) W-4: Polyoxyethylene phenyl ether W-5: Troysol
S-366 (manufactured by Troy Chemical Industries, Inc.) Solvents:
S1: Propylene glycol monomethyl ether acetate S2: Propylene glycol
monomethyl ether propionate S3: Ethyl lactate S4: Butyl acetate S5:
2-Heptanone S6: Propylene glycol monomethyl ether S7: Ethoxyethyl
propionate S8: y-butyrolactone S9: Ethylene carbonate S10:
Propylene carbonate S11: Cyclohexanone (2) Preparation and
evaluation of resist pattern
[0360] The resist film was subjected to electron beam irradiation
using an electron beam imaging device (HL 750 manufactured by
Hitachi, Ltd.; acceleration voltage: 50 KeV) . After the
irradiation, the resist film was baked at 110.degree. C. for 90
seconds, immersed in a 2.38% by weight aqueous solution of
tetramethylammonium hydroxide (TMAH) for 60 seconds to develop,
rinsed with water for 30 seconds and dried. The pattern thus
obtained was evaluated in the following manner:
[0361] (2-1) Sensitivity
[0362] The minimum irradiation energy necessary for resolving 0.15
.mu.m-line (line:space=1:1) was designated as the sensitivity.
[0363] (2-2) Resolution
[0364] Limiting resolution (line and space being separately
resolved) at the irradiation energy for obtaining the sensitivity
described above was designated as the resolution.
[0365] (2-3) Pattern Profile
[0366] A cross-sectional shape of 0.14 .mu.m-line pattern at the
irradiation energy for obtaining the sensitivity described above
was observed using a scanning electron microscope.
[0367] The results of evaluation obtained are shown in Table 3
below.
5TABLE 3 (Evaluation with Electron Beam (50 KeV) Resolution
Sensitivity Pattern (.mu.m) (.mu.C/cm.sup.2) Profile Example 101
0.060 3.0 Rectangle 102 0.060 3.0 Rectangle 103 0.065 3.0 Rectangle
104 0.060 3.0 Rectangle 105 0.065 3.0 Rectangle 106 0.070 2.5
Rectangle 107 0.075 2.5 Rectangle 108 0.075 2.0 Rectangle 109 0.075
2.0 Rectangle 110 0.075 2.5 Rectangle 111 0.080 2.0 Rectangle 112
0.075 2.5 Rectangle 113 0.075 5.0 Rectangle 114 0.080 5.5 Rectangle
115 0.080 2.0 Rectangle 116 0.065 2.0 Rectangle 117 0.070 2.5
Rectangle 118 0.065 2.5 Rectangle Comparative Example 101 0.12 9.0
Round top 102 0.12 9.5 Round top 103 0.12 8.5 Round top 104 0.13
8.5 Round top 105 0.13 9.5 Round top
EXAMPLES 116 TO 130 AND COMPARATIVE EXAMPLES 106 TO 110
[0368] A resist solution was prepared using the components shown in
Table 2 above in a same manner as in Example 101. The resist
solution was coated on a 6-inch silicon wafer using a spin coater
(Mark 8 manufactured by Tokyo Electron Ltd.) and baked at
110.degree. C. for 90 seconds to prepare a uniform film having a
thickness of 0.30 .mu.m.
[0369] The resist film was subjected to electron beam irradiation
using an electron beam imaging device (HL 750 manufactured by
Hitachi, Ltd.; acceleration voltage: 100 KeV). The treatment after
the irradiation and the evaluation were conducted in the same
manner as in Example 101.
[0370] The results of evaluation obtained are shown in Table 4
below.
6TABLE 4 (Evaluation with Electron Beam (100 KeV) Resolution
Sensitivity Pattern (.mu.m) (.mu.C/cm.sup.2) Profile Example 119
0.050 6.0 Rectangle 120 0.050 5.0 Rectangle 121 0.055 6.0 Rectangle
122 0.055 6.0 Rectangle 123 0.055 6.0 Rectangle 124 0.050 5.0
Rectangle 125 0.050 5.0 Rectangle 126 0.065 5.0 Rectangle 127 0.060
6.0 Rectangle 128 0.065 5.0 Rectangle 129 0.065 5.0 Rectangle 130
0.065 5.0 Rectangle 131 0.065 5.0 Rectangle 132 0.060 6.0 Rectangle
133 0.065 5.0 Rectangle 134 0.050 5.5 Rectangle 135 0.050 5.5
Rectangle 136 0.055 6.0 Rectangle Comparative Example 106 0.11 13.0
Round top 107 0.11 13.0 Round top 108 0.11 13.0 Round top 109 0.12
14.0 Round top 110 0.12 15.0 Round top
[0371] From the results shown in Tables 3 and 4, it can be seen
that the positive resist composition of the present invention
exhibits high sensitivity, high resolution and rectangular pattern
profile and has excellent properties.
EXAMPLES 137 TO 138 AND COMPARATIVE EXAMPLE 111
[0372] Using each of the resist solutions for Examples 101 and 102
and Comparative Example 101, a resist film was prepared in the same
manner as in Example 101 except for changing the thickness of the
resist film to 0.25 .mu.m. The resist film was subjected to
open-frame-exposure using an EUV beam (wavelength: 13 nm) while
changing the exposure energy amount 0.5 mJ each from 0 to 5.0 mJ,
and baked at 110.degree. C. for 90 seconds. Then, using a 2.38% by
weight aqueous solution of tetramethylammonium hydroxide (TMAH),
dissolution speed at each exposure amount was measured to obtain a
sensitivity curve. On the sensitivity curve, an exposure amount at
which the dissolution speed was saturated was designated as
sensitivity. Also, a dissolution contrast (.gamma. value) was
determined from a gradient of the sensitivity curve. As the .gamma.
value is larger, the dissolution contrast is better. The results
obtained are shown in Table 5 below.
7TABLE 5 (Evaluation with EUV) Sensitivity Example Composition
(mJ/cm.sup.2) .gamma. Value 137 Example 101 3.0 9.5 138 Example 102
2.0 10.5 Comparative Comparative >5.0 6.5 Example 111 Example
101
[0373] From the results shown in Table 5, it can be seen that the
positive resist composition of the present invention exhibits high
sensitivity and high resolution and has excellent properties in the
evaluation with EUV in comparison with the resist composition of
Comparative Example.
EXAMPLES 201 TO 214 AND COMPARATIVE EXAMPLES 201 TO 205
[0374] (1) Application of Resist Composition
[0375] Each of the components shown in Table 6 below in an amount
described below was dissolved in 18.0 g (in total) of the
solvent(s) to prepare a solution of negative resist
composition.
8 Alkali-soluble resin (BN) 2.0 g Acid generator in total 0.20 g
Crosslinking agent (C) in total 0.35 g Basic compound (if desired)
0.0080 g Surface active agent (if desired) 0.0040 g
[0376] The solution of negative resist composition was filtered
using a Teflon filter having a pore size of 0.1 .mu.m, then coated
on a silicon wafer subjected to a hexamethyldisilazane treatment
using a spin coater (Mark 8 manufactured by Tokyo Electron Ltd.)
and dried by heating at 110.degree. C. for 90 seconds on a vacuum
hot plate to prepare a resist film having a thickness of 0.3
.mu.m.
9TABLE 6 Surface Resin Crosslinking Acid Basic Active Example (BN)
Agent (C) Generator Solvent Compound Agent 201 a-(2) B-2 A1-3/II-4f
= S1/S3 = (4) W1/W2 = 3/2 80/20 2/1 202 a-(1) B-2/MM-1 = A1-4/I-9 =
S1/S6 = (4) W1 1/2 2/3 80/20 203 a-(93) B-5 A1-15/I-17 = S1/S7 =
(9) W1/W5 = 2/1 75/25 2/1 204 a-(29) B-17 A1-13/I- S1/S6/S10 = (1)
W1 37C = 1/1 65/20/15 205 a-(57) MM-1 A1-7 S1/S9 = (2) W1 90/10 206
a-(27) B-3 A1-1 S1/S11 = (6) W2 80/20 207 a-(1) B-4 A1-12 S1 (3) W1
208 a-(57) MM-1 A1-20 S3 (5) W1 209 a-(93) B-7 BCFY S1 (9) W5 210
a-(30) B-2 A1-4 S2 (8) W3 211 a-(27) MM-1 A1-8 S7 (9) W4 212 a-(39)
B-11 A1-3 S4 (6) W1 213 a-(91) HM-0 A1-5 S8 (7) W1 214 a-(32)
B-S/MM-1 = A1-14 S6 (1) W1 1/1 215 a-(2) B-2 A1-16/II-4f = S1/S3 =
(4) W1 3/2 80/20 216 a-(2) B-2 A1-17/II-4f = S1/S3 = (4) W1 3/2
80/20 217 a-(2) B-2 A1-19/II-4f S1/S3 = (4) W1 3/2 80/20 Surface
Comparative Resin Crosslinking Acid Basic Active Example (BN) Agent
(C) Generator Solvent Compound Agent 201 a-(2) B-2 I-1 S1/S3 (4)
W1/W2 = 80/20 2/1 202 a-(1) B-2/MM-1 = I-9 S1/S6 = (4) W1 1/1 80/20
203 a-(93) B-5 I-17 S1/S2 = (9) W1/W5 75/25 2/1 204 a-(30) B-1
PAG-1 S1 (3) W5 205 a-(91) B-17 PAG-2 S5 (2) W1 The composition
(molar ratio) and molecular weight of each of Resins a-(1), a-(2),
a-(3), a-(25), a-(27), a-(29), a-(30), a-(31), a-(32), a-(35),
a-(39), a-(57), a-(91) and a-(93) shown in Table 6 are as follows:
a-(1): Mw = 15,000 Mw/Mn = 1.1 a-(2): Mw = 9,000 Mw/Mn = 1.2 a-(3):
Mw = 8,000 Mw/Mn = 1.3 a-(25): x/y = 70/30 Mw = 16,000 Mw/Mn = 1.5
a-(27): x/y = 80/20 Mw = 9,500 Mw/Mn = 1.5 a-(29): x/y = 80/20 Mw =
9,200 Mw/Mn = 2.2 a-(30): x/y = 80/20 Mw = 12,000 Mw/Mn = 1.2
a-(31): x/y = 90/10 Mw = 8,500 Mw/Mn = 1.3 a-(32): x/y = 75/25 Mw =
9,000 Mw/Mn = 1.2 a-(35): x/y = 75/25 Mw = 20,000 Mw/Mn = 2.1
a-(39): x/y = 88/12 Mw = 11,400 Mw/Mn = 1.2 a-(57): x/y = 95/5 Mw =
5,000 Mw/Mn = 1.2 a-(91): x/y/z = 60/30/10 Mw = 11,000 Mw/Mn = 1.5
a-(93): x/y = 85/15 Mw = 9,300 Mw/Mn = 1.1 The abbreviations of
components used in Table 6 are explained below. Acid generator:
BCFY: 115 PAG-1: 116 PAG-2 117 Basic Compounds: (1):
1,8-Diazabicyclo[4.3.0]non-5-e- ne (2): 2,6-Diisopropylaniline (3):
4-Dimethylaminopyridine (4): 2,4,5-Triphenylimidazole (5):
Piperazine (6): 1,5-Diazabicyclo[4.3.O]non-5-ene (7):
Phenylguanidine (8): Hexamethylenetetramine (9): CHMETU Surface
Active Agents: W-1: Megafac F176 (manufactured by Dainippon Ink
& Chemicals, Inc.) (fluorine-based) W-2: Megafac R08
(manufactured by Dainippon Ink & Chemicals, Inc.) (fluorine-
and silicon-based) W-3: Polysiloxane polymer KP-341 (manufactured
by Shin- Etsu Chemical Industry Co., Ltd.) W-4: Polyoxyethylene
phenyl ether W-5: Troysol S-366 (manufactured by Troy Chemical
Industries, Inc.) Solvents: S1: Propylene glycol monomethyl ether
acetate S2: Propylene glycol monomethyl ether propionate S3: Ethyl
lactate S4: Butyl acetate S5: 2-Heptanone S6: Propylene glycol
monomethyl ether S7: Ethoxyethyl propionate S8:
.gamma.-butyrolactone S9: Ethylene carbonate S10: Propylene
carbonate S11: Cyclohexanone (2) Preparation and evaluation of
resist pattern
[0377] The resist film was subjected to electron beam irradiation
using an electron beam imaging device (HL 750 manufactured by
Hitachi, Ltd.; acceleration voltage: 50 KeV). After the
irradiation, the resist film was heated by a vacuum hot plate at
110.degree. C. for 60 seconds, immersed in a 2.38% by weight
aqueous solution of tetramethylammonium hydroxide (TMAH) for 60
seconds to develop, rinsed with water for 30 seconds and dried. A
cross-sectional shape of 0.15 .mu.m-line (line:space=1:1) pattern
formed was observed using a scanning electron microscope.
[0378] The minimum irradiation energy necessary for resolving 0.20
.mu.m-line (line:space=1:1) was designated as the sensitivity.
[0379] Limiting resolution (line and space being separately
resolved) at, the irradiation energy for obtaining the sensitivity
described above was designated as the resolution. When the 0.20
.mu.m-line (line:space=1:1) could not be resolved, limiting
resolution was designated as the resolution.
[0380] The results of evaluation obtained are shown in Table 7
below.
10 TABLE 7 Resolution Sensitivity Pattern (.mu.m) (.mu.C/cm.sup.2)
Profile Example 201 0.065 4.0 Rectangle 202 0.070 5.0 Rectangle 203
0.065 4.5 Rectangle 204 0.070 4.5 Rectangle 205 0.075 6.5 Rectangle
206 0.075 8.0 Rectangle 207 0.085 5.0 Rectangle 208 0.075 6.0
Rectangle 209 0.080 5.0 Rectangle 210 0.085 4.5 Rectangle 211 0.075
6.0 Rectangle 212 0.085 6.0 Rectangle 213 0.080 6.5 Rectangle 214
0.080 5.5 Slightly round top 215 0.065 5.5 Rectangle 216 0.070 5.5
Rectangle 217 0.070 6.0 Rectangle Comparative Example 201 0.12 12
Round top 202 0.13 10 Round top 203 0.12 11.5 Round top 204 0.13 12
Round top 205 0.13 10.5 Round top
[0381] From the results shown in Table 7, it can be seen that the
negative resist composition of the present invention exhibits high
sensitivity, high resolution and rectangular pattern profile and
has excellent properties.
[0382] In case of using an X-ray imaging device for exposure,
similar results were obtained.
[0383] According to the present invention, a positive or negative
resist composition for an electron beam, EUV or X-ray, which is
excellent in sensitivity and resolution and provides rectangular
profile, can be provided.
[0384] The entire disclosure of each and every foreign patent
application from which the benefit of foreign priority has been
claimed in the present application is incorporated herein by
reference, as if fully set forth herein.
[0385] While the invention has been described in detail and with
reference to specific embodiments thereof, it will be apparent to
one skilled in the art that various changes and modifications can
be made therein without departing from the spirit and scope
thereof.
* * * * *